Glossary of AMI Terms

Click on this link to view an online Glossary of Parking Technology Terms.

The following table provides definitions for common technical and industry terms used by Amano McGann, Inc.



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2D data matrix2D barcode data matrix encodes data with very high density. Data matrix symbols are printed in square or sometimes a rectangular pattern. Each dot of a data matrix symbol represents a bit. This is in contrast to linear barcodes, where the information is encoded in the ratio of the bars or spaces to each other.
2FATwo-factor Authentication. A specific type, or subset, of multi-factor authentication (MFA) that strengthens access security by requiring two methods (also referred to as authentication factors) to verify a user's identity. It is a method of confirming users' claimed identities by using a combination of two different factors: 1) something they know, 2) something they have, or 3) something they are.


ABAAmerican Banking Association.
Access TerminalA reader designed to be installed in a lane on a pedestal. The technology is dependent upon the requirements of the facility and may include one or more of the following: mag-stripe, linear barcode, proximity, or AVI, in addition to options for messaging display and intercom.
ACKAcknowledge. Received data valid.
acquiring bankThe bank where the merchant's merchant account is held, and from which funds are transferred daily into the merchant's local bank account.
ADAAmericans with Disabilities Act. A civil rights law that prohibits discrimination based on disability.
administratorAn individual who is responsible for the parking system hardware and/or software and its users. See alsoUser.
AESAdvanced Encryption Standard. A symmetric-key block cipher algorithm chosen by the U.S. government to protect classified information. In December 2001, the National Institute of Standards (NIST) approved AES, which specifies application of the Rijndael algorithm to encrypt all sensitive or classified data. AES is now used as a standard for secure data encryption and decryption in software and hardware throughout the world.
AGPAccelerated Graphics Port. High speed point-to-point channel for attaching video cards on a mainboard.
AMGAmano McGann Global Products. Hardware integrated with a ticket printer/encoder that utilizes magnetic stripe technology and tickets.


Amano-McGann Inc.

anti-remAnti-removal. A anti-tamper security feature of hardware devices and components.
ANPRAutomatic Number Plate Recognition. Includes License Plate Recognition (LPR).
ANSIAmerican National Standards Institute. A private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.
anti-passbackCredential is checked and is either denied use (Hard Anti-Passback) or accepted (Soft Anti-Passback) but an event is recorded and marked as passback. Note: depending on individual system settings, this may prevent an individual from entering/leaving.
Apriva®A commercial transaction payment portal.

Application Program Interface. An API is a set of routines, protocols, and tools for building and integrating application software. It’s sometimes referred to as a contract between an information provider and an information user—establishing the content required from the consumer (the call) and the content required by the producer (the response). Basically, an API specifies how software components should interact. Additionally, APIs are used when programming Graphical User Interface (GUI) components.

ASCIIAmerican Standard Code for Information Interchange. A character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices.
ASICApplication Specific Integrated Circuit. A microchip designed for a special application – such as a particular kind of transmission protocol or a hand-held computer – unlike general integrated circuits such as the microprocessor and the random access memory RAM IC's in a PC.
ASP.NET.NET is a developer platform made up of tools, programming languages, and libraries for building many different types of applications. The base platform provides components that apply to all different types of apps. Additional frameworks, such as ASP.NET, extend .NET with components for building specific types of apps.
AUTApplication Under Test – refers to an application that is currently being tested by the Amano McGann Quality Assurance team.
authenticationThe process of recognizing a user’s identity or of associating an incoming request with a set of identifying credentials. The credentials provided are compared to those on a file in a database of the authorized user’s information on a local operating system or within an authentication server. In contrast with identification, the act of indicating a person or thing's identity, authentication is the process of verifying that identity. The five most common types of authentication include: 1) Password-based authentication; 2) Multi-factor authentication; 3) Certificate-based authentication; 4) Biometric authentication; 5) Token-based authentication.
authenticationAn authentication token allows internet users to access applications, services, websites, and application programming interfaces (APIs) without having to enter their login credentials each time they visit. An authentication token securely transmits information about user identities between applications and websites.
AVIAutomatic Vehicle Identification. Autonomous identification techniques used with moving objects such as vehicles and includes License Plate Recognition (LPR), Radio Frequency Identification (RFID) as the object passes a RFID reader, and long range proximity sensing.
AWSAmazon Web Services. A comprehensive, evolving cloud computing platform provided by Amazon that includes a mixture of Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and packaged Software as a Service (SaaS) offerings.


back-out featureA feature that allows parking patrons to reverse out of lane after they've taken a ticket.
barrier gateA barrier gate is a bar or boom that lowers to block vehicular access through a controlled point. When access is granted, the bar or boom rises vertically to allow vehicles to pass.
baudA measure of the number of bits per second of a digital signal. For example, a 1200 baud signal transmits 1200 bits per second. 
BINBank Identification Number. The first six digits (or more) of a payment card number that identifies the financial institution that issued the payment card to the cardholder. 
BLEBluetooth Low Energy. A part of the Bluetooth V4 protocol. Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz). Bluetooth devices comply with the Bluetooth SIG standard.

Bluetooth Low Energy (aka Bluetooth LE, BLE, marketed as Bluetooth Smart™) is a power-friendly version of Bluetooth wireless technology used on devices that run off a small battery for long periods.

Bluetooth®Wireless protocol using short-range communications technology to facilitate transmission of data over short distances.
BNABank Note Acceptor (also; bill acceptor, paper currency detector, bill validator). A purpose-designed device for acceptance of paper currency used in all types of equipment with automatic operation. A BNA can not only identify the nominal value of the banknote that has been inserted, but can also test its authenticity with high precision in a relatively short time.
BNRBank Note Recycler. A cash-handling unit that accepts accepts, organizes, stores and dispenses bank notes. In a BNR, bank notes are placed into a feeder and then pass through a bank note identifier to determine the denomination and validity of the banknotes.
BRFBezel Radio Frequency. A continuous, uninterrupted outer perimeter of a Near Field Reader (NFR) made of an electrically conductive material and used as a radio-frequency sensitive antenna for Near Field Communication (NFC). A handheld device or pass-card, comprising a conductive mass or shortwave transmitter, is positioned in or near the bezel, which activates the Near Field Reader in either a common excitation mode or a differential excitation mode to enable communication.


CAL licenseClient Access License. A commercial software license that allows client computers to use server software services. A CAL legally permits client computers to connect to commercial server software. They usually come in the form of a Certificate of Authenticity (CoA) and a license key, which is sometimes attached to the certificate itself.
Card Data / Customer Card DataAt a minimum, card data includes the Primary Account Number (PAN), and may also include cardholder name and expiration date. The PAN is visible on the front of the card and encoded into the card’s magnetic stripe and/or the embedded chip. Also referred to as cardholder data. See also Sensitive Authentication Data for additional data elements which may be part of a payment transaction, but which must not be stored after the transaction is authorized.
CCTVClosed Circuit Television. Typically used in surveillance camera systems or recognition systems, such as License Plate Recognition.

Chip Card Interface Device. CCID protocol is a USB protocol that allows a smart card to be connected to a computer via a card reader using a standard USB interface, without the need for each manufacturer of smart cards to provide its own reader or protocol.

This allows the smartcard to be used as a security token for authentication and data encryption purposes. Chip card interface devices come in a variety of forms. The smallest CCID form is a standard USB dongle and may contain a SIM card or Secure Digital card inside the USB dongle. Another popular interface is a USB smart card reader keyboard, which in addition to being a standard USB keyboard has an built-in slot for accepting a smartcard.

CCIOCredit Card In/Out. Ticketless entry/exit of a vehicle within a parking facility.
CDC-ACM (USB)A USB communications device class used for industrial equipment that supports integrating newer devices using older RS-232 serial port communications while maintaining software compatibility. A USB serial port device can be plugged into a host device's USB port and recognized by the host as a remote serial port. The OS in the USB device makes it appear to the host as a traditional RS-232 port.
Central Pay StationA conveniently located Fee Computer, Pay-on-Foot or ExpressParc device that allows patrons to pay for parking prior to returning to their vehicle by using their Entry Ticket as the method for fee calculation. See also, Entry Ticket.
chipAlso known as EMV Chip. The microprocessor (or “chip”) on a payment card used when processing transactions in accordance with the international specifications for EMV transactions.
Chip and PinA verification process where a consumer enters their PIN in an EMV Chip-enabled payment terminal when they purchase goods or services.
click-jackingA capture technique used by cyber-criminals to trick users into clicking on a seemingly innocuous link, object, or web page with an expected result or destination, but who instead are routed to the attacker's chosen destination, often for malicious purposes. Click-jacked users thus may potentially reveal confidential information or allow others to take control of their computer. Click-jacking is more formally known as a User Interface redress attack, UI redress attack, UI redressing, or IFRAME overlay.

The client–server model is a distributed application structure that partitions tasks or workloads between the providers of resources or services, called servers, and service requester, called clients. Servers and their clients typically reside on separate hardware devices and communicate over a computer network, but a server and its clients may reside within the same system, or even on the same computer. Examples of computer applications that use the client–server model are email servers and clients, network printing services, and the world wide web.

In the client-server model, a host server runs one or more application programs, which provide resources to server requester, or clients. A client does not share any of its resources, but it requests content or services from the host server. Clients therefore initiate communication sessions with servers, which await incoming requests to provide services.

In early client–server computing models, the processing load for an application was shared between code installed on the server and code installed on each client locally. In other words, an application had its own pre-compiled client program – which served as its user interface – and had to be separately installed on each user's PC or workstation. An upgrade to the server-side code of the application would typically also require an upgrade to the client-side code installed on each user workstation, adding to the support cost and decreasing productivity. In addition, both the client and server components of the application were usually tightly bound to a particular computer platform and OS. Porting them to work on other platforms and operating systems was often prohibitively expensive for all but the largest applications.

In later client–server computing models, web applications (or web apps) liberated application resource-sharing between servers and clients. A web app is an application program that the user runs within a web browser, that runs on a host server, and is delivered over the Internet. Popular web apps include webmail such as Gmail, Google Apps and Microsoft 365. Other examples of web apps are internet-based word processors, spreadsheets, file conversion, video streaming, and online banking. In a web app, the user may not only view pages of content to access resources, but also can manipulate content and resources remotely. Web services are web apps by definition and most websites contain web apps.

cloud computingA general term for various hosted services delivered over the internet. Cloud computing uses remote, rented servers accessed via the internet to store and manage data, rather than a local, privately-maintained, on-premise server. Prior to cloud computing, websites typically were hosted on a local server. To ensure minimum downtime, site owners had to buy sufficient server bandwidth to accommodate peak traffic volume, which meant that a large amount of server space went unused for much of the time.
cloud services

IT services delivered on-demand via the internet. Cloud services are designed to provide easy access to applications and resources without the need for internal infrastructure or hardware. Cloud services are fully managed by cloud computing service providers, so there's no need for a company to host the applications using on-premise servers. Cloud services are more cost-effective than on-site server installations and may even provide faster service than a traditional installation.

CoACertificate of Authenticity. A seal or small sticker on a proprietary computer program to demonstrate that the item is authentic. Computer COA's have a license number on them, which verifies that the program is a genuine, legal copy.
COASCoin-On-A-String. A type of fraud sometimes used with coin pay devices.
codecA device or computer program which encodes or decodes a digital data stream or signal. Codec is a portmanteau of coder-decoder. The coder function encodes a data stream or a signal for transmission or storage, possibly in encrypted format, and the decoder function reverses the encoding for playback or editing. Codecs are used in videoconferencing, streaming media, and video editing applications.
COMSerial Communication Port. In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels.

iParc feature (and module) that tracks the number of patrons that enter and exit the parking lot.  The data collected is used to calculate the number of patrons that are currently inside the parking lot.  The derived value can be used determine the lot status such as "FULL" and other messages to prevent patrons from entering when there are no available parking spaces.

CRCCyclic Redundancy Check. An error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data. Blocks of data entering these systems get a short check value attached, based on the remainder of a polynomial division of their contents.
CredentialInformation used to identify and authenticate a user for access to a system. For example, credentials are often the user name and password. Credentials may include a fingerprint, retina scan, or a one-time number generated by a portable “token-generator.” Security is stronger when access requires multiple credentials.
CTSClear-To-Send. A signal between computers that indicates that data transmission can proceed.
customerThe individual or company that owns or manages the parking hardware and software system.
CVMCardholder Verification Method. Credit and debit cards can require a cardholder verification method (CVM), when used in a payment terminal, to verify that the person using the card is the legitimate cardholder. Verification is commonly done with a personal identification number or shopper signature.
CVPSComputerized Valet Parking System. Also, Creating Vision in Parking Systems.


DBCSDatabase Connection String. A connection string is a string that specifies information about a data source and the means of connecting to it. It is passed in code to an underlying driver (or provider) to initiate the connection. Though commonly used for a database connection, the data source could also be a spreadsheet or text file. The connection string typically includes attributes such as the name of the driver, the server and/or database names, as well as security information such as username and password.
DESData Encryption Standard. An outdated symmetric-key method of data encryption. DES works by using the same key to encrypt and decrypt a message, so both the sender and the receiver must know and use the same private key.
default passwordA simple password that comes with new software or hardware. Default passwords (like “admin” or “password” or “123456”) are easily guessed and must be changed to a stronger password after installing new software or hardware.
deviceGeneral term for equipment like entry and exit terminals, pay stations, etc.

Dynamic Host Configuration Protocol. A protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. In the Overture environment, it is used to give the IP address and the location of the boot image to the field devices.

Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. This means that a new computer can be added to a network without the hassle of manually assigning it a unique IP address. Many ISPs use dynamic IP addressing for Internet subscribers.

DPIDots Per Inch.
DTFDual Ticket Feed.
DUKPTDerived Unique Key Per Transaction. A key management scheme that uses one-time encryption keys derived from a secret master key that is shared by the entity (or device) that encrypts and the entity (or device) that decrypts the data. In OPUS devices, DUKPT is used to encrypt credit card track data at the read-head before it is transmitted to a payment gateway via a TLS encrypted connection.
DVIDigital Visual Interface. A video display interface developed by the Digital Display Working Group (DDWG). The digital interface is used to connect a video source to a display device, such as a computer monitor.


E2EEEnd-to-End Encryption. A system of encrypted communication where only the communicating users can read the messages. Messages are encrypted by the sender but the third-party does not have a means to decrypt them, hence they are stored encrypted. The recipient retrieves the encrypted data and decrypts it themselves. See also, P2PE.
EFTPOSElectronic Funds Transfer at Point of Sale. An electronic payment system for electronic transfer of funds based on the use of payment cards, such as debit and credit cards, at payment terminals located at points of sale. EFTPOS technology originated in the United States in 1981 and was adopted by other countries. Debit and credit cards are embossed plastic cards complying with ISO/IEC 7810 ID-1 standard. The cards have an embossed bank card number conforming with the ISO/IEC 7812 numbering standard.
EMVAn acronym of Europay, Mastercard, Visa standard.
Entry / Exit StationAny of various of entry and exit lane terminals designed for multiple uses, typically at unattended entrances of a parking facility. They can be equipped with ticket dispensing, access card and credit card functionality. Later devices are PCI compliant.
Entry / Exit TicketEntry Ticket – a ticket issued from an Entry Station and used to calculate a transient parking fee. Exit Ticket – a ticket previously paid and encoded at a Central Pay Station.
ECDSAElliptic Curve Digital Signature Algorithm. A Digital Signature Algorithm (DSA) that uses keys derived from elliptic curve cryptography (ECC). It is a highly efficient equation used across many security systems, is popular for use in secure messaging apps, and it is the basis of Bitcoin security (with Bitcoin “addresses” serving as public keys). ECDSA is also used for Transport Layer Security (TLS), the successor to Secure Sockets Layer (SSL), by encrypting connections between web browsers and a web application. The encrypted connection of an HTTPS website, illustrated by an image of a physical padlock shown in the browser, is made through signed certificates using ECDSA.
ERSException Review Station. Information that is generated during ERS Sessions when a patron is unable to exit a facility due to a lost ticket or credential mismatch error. See also, ERS Sessions.
ERS SessionsA feature that enables users to view a list of exceptions to normal payment transactions when ERS/License Plate Recognition (LPR) features are installed and in use.
ETCElectronic Toll Collection. A method of collecting toll fees electronically without cash and without requiring cars to stop to eliminate the delays on toll roads, HOV lanes, toll bridges, and toll tunnels. A transponder is used within the vehicle that is sensed by a signal sensor, or reader, that records the time and place the transponder passed. The signal data is relayed to central computer database, which then calculates the toll fee. Similar methods for capturing and computing parking fees in a "ticketless" parking system are currently being developed.
ETLExtract-Transform-Load. ETL is the process that pulls data from a data source, extracts it, transforms it, and loads it, into an SQL Server. A tool called Microsoft SQL Server Integration Tools (SSIS) handles ETL processes.
EVElectric Vehicle. A vehicle that uses one or more electric motors or traction motors for propulsion.
ExpressParc®A term used for mag-stripe AMG devices that accept credit card only as a method of payment for transient parking and iParc Pro+ modules for fee calculation and credit card payment processing. ExpressParc supports credit card in/credit card out, credit card out with entry ticket, and credit card central pay with entry or exit ticket. ExpressParc devices include the ExpressParc Entry Station (AMG-2570 series), ExpressParc Exit Station (AMG-4570 series) and ExpressParc Central Pay Station (AMG-4300 series).


failoverFailover is a backup operational mode that automatically switches to a standby database, server, or network, if the primary system fails or is shut down for servicing. Failover is an important function for critical systems that require always-on accessibility.


File Allocation Table.


Fee Computer.

Fee ComputerAn attended POS or cashier terminal. Fee Computers are PCI compliant terminals that perform automatic parking fee calculations automatically from a mag-stripe parking ticket when the ticket is inserted into the Validator. Multiple fee computers and validators may be utilized in conjunction with several types of ticket dispensers for a complete on-line parking revenue control system.
Fee DisplayA device connected to a Fee Computer to display parking fees, duration of stay and change back to the parking patron.
field deviceGeneric terms for AMI equipment such as entry or exit terminals, pay stations, fee computers and so forth.
firewallHardware and/or software that protects network resources from unauthorized access. A firewall permits or denies communication between computers or networks with different security levels based upon a set of rules and other criteria.
firmwareFixed data, semi-permanently stored in hardware such as a PROM chip.
FlexScan®FlexScan is a term used for devices manufactured by AMI with an integrated reader pocket for the optional barcode imager. FlexScan is designed to accommodate a variety of applications that use barcode technology. When used on-line with the iParcProfessional PARCS system, and interfaced with the required add-on software modules, components, and third-party applications, FlexScan will support expanded features such as pre-paid parking credentials, pay-by-phone, and barcode validation coupons.
FTPFile Transfer Protocol. A network protocol to transmit files over an IP-based network.
FQDNFully Qualified Domain Name. The complete domain name for a specific computer, or host, on the internet. The FQDN consists of two parts: the hostname and the domain name. For example, the FQDN for a mail-server might be


gatewayA device that regulates data traffic between dissimilar networks.
GNDSignal ground. Also, Earth ground.
grace timeThe time allowed between entering a facility and leaving it that does not incur a fee. Grace time is used frequently in places like airports and bus terminals where drivers may be picking up and dropping off travelers.
GUIGraphical User Interface. A graphical interactive front-end to make application software faster and easier to use.
GUIDGlobally Unique Identifier. A 128-bit integer number used to identify resources. The term GUID is generally used by developers working with Microsoft technologies, while UUID is used everywhere else.
GPIOGlobal Purpose Input Output. An uncommitted digital signal pin on an integrated circuit or electronic circuit board that does not have a specific function. While most pins have a dedicated purpose, such as sending a signal to a certain component, the function of a GPIO pin is customizable and can be controlled by software.
Hall Effect SensorA device used to measure the magnitude of a magnetic field. Its output voltage is directly proportional to the magnetic field strength through it. Hall effect sensors are used for proximity sensing, positioning, speed detection, and current sensing applications.
HIDHuman Interface Device


IAXInter Asterisk Exchange protocol: Used for VoIP connections between VoIP servers.
IISInternet Information Services. IIS is a web server software package designed for Windows Server. It is used for hosting websites and other content on the web.
IMEIInternational Mobile Equipment Identity. Think of it as a smart-phone's fingerprint – it's a 15-digit number unique to each mobile device. Phone carriers and manufacturers share IMEI numbers to enable tracking of smartphones that may be stolen or compromised.
ISOInternational Organization for Standardization.


JISJapanese Industrial Standard.
jPOSJava Point of Sale. A free and open source library/framework that provides a high-performance bridge between card messages generated at the point of sale, or ATM terminals, and internal systems along the entire financial messaging network. jPOS is an enabling technology that can be used to handle all card processing from messaging, to processing, through reporting.


keyboard wedge

Keyboard wedges can be either hardware or software wedges. A hardware keyboard wedge is a device that “wedges” between the keyboard and computer unit and helps translate data read by another device into keyboard data. When you use a keyboard wedge with a barcode scanner, it will convert all barcode characters to keyboard keystrokes and send it to the database in use. The computer actually thinks that any data scanned is being typed in on the keyboard.

A software keyboard wedge provides the same function, but in a different way. A software keyboard wedge connects directly to the COM port and not to the keyboard. Data from the barcode scanner is sent to the COM port and is rerouted to the keyboard buffer. Once again, the computer believes the information is coming directly from the keyboard.

keyless entry

KPIKey Performance Indicator. A well-defined, strategic measurement of a quantifiable value that demonstrates how effectively a company is achieving key business objectives. Organizations use KPIs at multiple levels to evaluate their success at reaching targets. The difference between KPI and KPM is that these types of measurements relate to a specific strategic business goal and reflect how successful the business is in achieving that goal.
KPMKey Performance Metric. A well-defined, tactical measurement of a quantifiable value that tracks some aspect of business activity and measures success or failure in the performance of that activity. KPMs must be quantifiable to specifically state results that show how well actual activities or performance compares with respect to set targets.
KSNKey Serial Number. Also, Knowledge Sharing Network. 


lag timeThe time interval between paying for parking at a central pay station and leaving the facility. Lag time is variable and configurable, but usually on the order of 10 minutes.
Lag-Time ReaderAn Exit Station installed in the exit lane of a parking facility to read a mag-stripe exit ticket previously paid and encoded at a central pay location.  Additional functionality may include an integrated proximity reader for contract parker egress, FlexScan barcode imager to accept pre-paid parking credentials used on entry or valet tickets.  This device may also be installed in nested locations to re-encode an alternate rate.
LANLocal Area Network. Example: the TCP-IP network in a building.
logA file that is created automatically when certain predefined (often security-related) events occur within a computer system or network. Log data includes date/time stamp, description of the event, and information unique to that event. These files are useful for troubleshooting technical issues or a data breach investigation. Also called an audit log or audit trail.
LPILicense Plate Identification. The combination of a handheld device and a database to allow a person to manually capture a license plate and log it into a database for future reference.
LPRLicense Plate Recognition. LPR uses the combination of a camera and database to allow the camera to capture a license plate image, convert the image to alpha numeric text and compare that text to a database of registered plates.
LRCLongitudinal Redundancy CheckAlso, Horizontal Redundancy Check. A form of redundancy check that is applied independently to each of a parallel group of bit streams. The data must be divided into transmission blocks, to which the additional check data is added.
LVDSLow Voltage Differential Signaling. An electrical digital signaling standard that can run at very high speeds over inexpensive twisted-pair copper cables. This technology is used for the TFT display in certain AMI Overture devices.


MACMessage Authentication Code. A cryptographic checksum on data that uses a session key to detect both accidental and intentional modifications of the data. This allows the recipient of the message to verify the integrity of the message and authenticate that the message's sender has the shared secret key.
MAC addressMedia Access Control address. The physical unique identification number for network devices, to identify a computer in a computer network.

Manual. A term used for technical documentation.

Mass Validation Production System (MVPS)A PC-based validation coupon production system designed to provide off-line bulk encoding of magnetic stripe coupons for parking management to issue to valid merchants to distribute to their patrons.
MFAMulti-factor Authentication. An authentication method in which a user is granted access only after successfully presenting two or more pieces of evidence (or factors) to an authentication mechanism: knowledge (something the user and only the user knows), possession (something the user and only the user has), and inherence (something the user and only the user is).
MIDMerchant ID or merchant identification.
merchant bankA bank or financial institution that processes credit and/or debit card payments on behalf of merchants. Also called an acquirer, acquiring bank, card processor, or payment processor. See also Payment Processor.
merchant accountA special bank account that enables a business to accept payment by credit card for goods and services. Credit card payments can only be processed through a merchant account. For  'electronic/ecommerce' payments, an electronic merchant number setup specifically for accepting online payments is required.
MIFAREA portmanteau derived from the term Mikron FARE Collection®, a trademark of NXP Semiconductors. MIFARE describes a series of integrated circuit (IC) chips used in contactless smart cards and proximity cards. MIFARE is a "contactless" technology that employs an RFID between the card and the reader and so do not require insertion of the card into a read head. Instead, the card is held near the exterior of the reader. Encryption keys prevent data from being emitted until the MIFARE card and card reader mutually authenticate each other.
mobile deviceGeneral term for a class of consumer electronic devices such as portable, digital electronic equipment that can connect to the internet and other computer networks wirelessly. Mobile devices include smartphones, tablets, tablet computers, and wearable key fobs.
mobile keyless entry

A secure access technology that enables hotel guests to check in and access hotel parking facilities and their assigned guest rooms using their mobile device, which is equipped with a mobile key. Some mobile keys operate via touchscreen keypad and others via Bluetooth smart key.

When keyless entry is implemented at a facility, employees and customers enjoy the convenience of using their mobile device as an entry or access key to assigned areas without having to carry or keep track of a separate physical key.

mobile keyAlso known as a digital key, a mobile key enables users, such as hotel guests, to unlock a door and enter a facility using an app on their mobile device, which is significantly more convenient and efficient than using a plastic room key. The door opens with the mobile key when the phone touches the lock, or when the lock reads a BLE passcode token on the mobile device, or when a scanner reads a barcode image on the display.
mobile key reader

In a mobile keyless entry security system, a mobile key reader is used to read the mobile key of a guest's mobile device to grant access to a secured facility. In the case of Hotel Mobile Key applications, the mobile key enables guests to access their hotel room, to open secured exterior doors, and to enter hotel parking facilities.

A hotel or other facility's parking management system (PMS) transmits the guest's encrypted mobile key passcode to the guest's mobile device, where it is securely stored in a key vault on a mobile app. The mobile key passcode also is transmitted to the mobile key reader.  When the guest's mobile device is presented to a corresponding mobile key reader, such as a door lock, the app transmits the encrypted mobile key information over a secure communication channel to the reader, thus ensuring that only authorized users are able to gain access. Encrypted mobile key passcodes may be formatted as mag-stripe, RFID, or Bluetooth mobile key credentials. Compatible mag-stripe, RFID, and/or BLE readers must be installed at each access point.

mobile payment  acceptanceUsing a mobile device to accept and process payment transactions. The mobile device is usually paired with a commercially available card reader device.
MOTOMail Order / Telephone Order. Credit card transactions wherein the merchant never gets a signature from the customer, but only their credit card number and expiration date.
MSRMagnetic Stripe ReaderAlso, mag-stripe reader. A hardware device that reads the information encoded in the magnetic stripe located on the back of a plastic badge or credit card. The magnetic stripe on the back of a badge is composed of iron-based magnetic particles encased in plastic-like tape.


NAKNot Acknowledge. Received data invalid.
NFCNear Field Communication (NFC). A short-range wireless connectivity standard (e.g., Ecma-340, ISO/IEC 18092) that uses magnetic field induction to enable communication between devices when they're touched together, or brought within a few centimeters of each other.
NFC paymentContactless payments that use NFC technology to exchange data between readers and payment devices like Apple Pay® and Google Pay® e-Wallets in smartphones and smartwatches, or tap-to-pay credit and debit cards.
NFRNear Field Reader. A type of pass card or device reader that employs Near Field Communications.
NICNetwork Interface Card. A hardware component, typically a circuit board or chip, that is installed on a computer so that it can connect to a network.


OLEObject Linking and Embedding. A component document technology developed by Microsoft that allows users to dynamically link files and applications. An object is a combination of data and the application needed to modify that data.
OLVOnline Validations Solution. A ticket validation and fee-discounting system that enables site administrators to issue parking validations and create barcode-based parking passes.
OPUSAmano McGann devices and software. Hardware is integrated with a ticket printer/encoder that utilizes encrypted barcode technology.
OSOperating System. There are many different types of computer operating systems. Windows OS is the most common.
OTPOne Time Programmable. OTP is a semiconductor device that can be programmed only once and it cannot be changed or reused after its initial programming. PROM and PAL are One Time Programmable semiconductor devices.


P2PEPoint-to-Point Encryption. A standard established by the PCI Security Standards Council. Payment solutions that offer similar encryption but do not meet the P2PE standard are referred to as End-to-End encryption (E2EE) solutions. Both P2PE and E2EE solutions encrypt payment data at the point-of-interaction with the payment method (e.g., card swipe/MSR, Dip/EMV, Tap/NFC). From there, the transaction data is transported to the solution provider which, depending on the type of solution, will occur within a non-integrated, semi-integrated, or fully-integrated environment. See also, E2EE.
PA-DSSPayment Application – Data Security Standard. A set of requirements intended to help software vendors develop secure payment applications that support PCI DSS compliance. PA-DSS applies to third-party applications that store, process or transmit payment cardholder data as part of an authorization or settlement.
pairingTwo devices that must be used together for security reasons are paired devices.
PANPrimary Account Number (credit card number). A key piece of cardholder data that a business is obligated to protect under the PCI DSS. Storing the full PAN data for customers exponentially increases the security risk and, consequently, it's scope of compliance. See salted.
PARCSParking Access and Revenue Control System. Real-time computerized parking systems for transient and credentialed customers. Available in varying levels of functionality and complexity, these systems allow parking owners and operators to control access and collect parking revenues from users.
patronAn individual who pays to park in the facility as either a transient or contract parker.
Pay StationPay stations are PCI Compliant terminals that accept entry tickets, expired exit tickets, validated tickets, and validation coupons. They also calculate parking fees, accept and process credit cards, print and issue a receipt on request, and issue a paid exit ticket. There are two main types of Pay Stations: Pay-on-Foot (POF) and Pay-in-Lane (PIL).

Use of a smartphone to interact with fee transaction services such as a PARCS system. Pay-by-Phone enables customers to use the camera on their smartphone to transact payments remotely without having to download an application. For example, to pay a parking fee, the patron might scan a 2D barcode on an entry ticket, which launches a secure payment website. The patron can view the fee due, apply validations or discounts, and choose to receive a receipt via SMS or email. The patron approves and pays the parking fee and that information is transmitted back to the PARCS system, where the payment is recorded and the entry ticket is re-designated an exit ticket. The customer uses the ticket at an exit terminal to exit the facility.

payment gatewayA payment gateway links a web site to the business's credit card processing companies and merchant account. When a patron swipes a credit card, the payment gateway obtains authorization for the charge, which will then settle into the merchant account.
Pay-On-Foot (POF)A conveniently located unattended device that allows patrons to pay for their parking prior to returning to their vehicle by using their entry ticket as the method of fee calculation.  The device may interchangeably refer to an ExpressParc credit card only pay-on-foot station or an automated pay-on-foot machine that provides options to accept credit card, coin and notes for payment and for dispensing change in notes and coins
payment processorEntity engaged by merchants to handle payment card transactions on their behalf. While payment processors typically provide acquiring services, payment processors are not considered acquirers (merchant banks) unless defined as such by a payment card brand. Also called a payment gateway or payment service provider (PSP). See also Merchant Bank.
payment terminalHardware device used to accept customer card payments via swipe, dip, insert, or tap. Also called point-of-sale (POS) terminal, credit card reader, or PDQ terminal.
PBXPrivate Branch eXchange. A telephone system within an enterprise that switches calls between enterprise users on local lines while allowing all users to share a certain number of external phone lines. PBX in Overture communications is IP-PBX in reality. An IP (Internet Protocol) PBX (Private Branch eXchange) is a business telephone system designed to deliver voice or video over a data network and interoperate with the normal Public Switched Telephone Network (PSTN).
PCIPayment Card Industry.
PCI-DSSPayment Card Industry - Data Security Standard.
PCI-SSCPayment Card Industry - Standards Security Council. An information security standard for organizations that handle branded credit cards from the major card schemes. The PCI Standard is mandated by the card brands and administered by the Payment Card Industry Security Standards Council.
PCI - PTSPayment Card Industry - PIN Transaction Security.
PEDPIN Entry Device. Keypad into which the customer enters their PIN. Also called a pin-pad.
PGSParking Guidance System. Parking Guidance Systems – alternately Car Park Guidance (CPG) systems – present drivers with dynamic, real-time information on parking within controlled areas. The system combines intelligent traffic monitoring, communication, processing and variable message sign technologies to provide the service.
PIDUSB Product ID. USB Product IDs (PID) are 16-bit numbers used by manufacturers to identify USB devices to a computer or other host. See also, VID.
PILPay-in-Lane. An in-lane cashier station or booth in the entry lane to a parking facility that may be used to collect payment for parking; dispense tokens, tickets, or other items indicating time of entry or validity of vehicle; or to detect credentials or other permissions enabling entry.
PINPersonal Identification Number. A unique number known only to the user and a system to authenticate the user to the system. Typical PINs are used for automated teller machines for cash advance transactions, or for EMV chip cards to replace a cardholder’s signature. PINs help determine whether a cardholder is authorized to use the card and to prevent its unauthorized use if the card is stolen.
Pin-padA 10-digit keypad used to enter a PIN.
PMSProperty Management System (hotel interface). Also, Parking Management System.
PoEPower over Ethernet. Alternately, POE. A technology that delivers both power and data simultaneously on twisted pair Ethernet cable to improves network agility and expand scalability in an efficient way. There are various styles of PoE devices, such as a PoE switch, PoE injector, PoE splitter, etc.
POE injectorA PoE injector, also called midspan or PoE adapter, connects a PoE-enabled network device to a non-PoE LAN switch port. A PoE injector is used to make a non-PoE compatible switch work with PoE devices by powering compliant devices over a single, twisted-pair Ethernet cable. A typical application is for low-power devices set up in locations where a power outlet is unavailable. It provides greater flexibility by enabling installation of devices in hard-to-reach areas, with a minimal impact on existing structures and budgets.
POFPay-On-Foot. A pay station terminal residing outside of an exit lane where parking patrons can redeem validations and pay parking fees before exiting a parking facility. Opposite of Pay-In-Lane.
POIPoint of Interaction. The initial point where data is read from a card. A POI is a hardware and/or software component point of sale equipment (e.g., a mag-stripe or EMV card reader) that enables a customer to use a credit card to make a purchase. The POI may be attended or unattended.
POSPoint-of-Sale. A POS device is a machine that enables processing of a transaction and capture of funds. A POS terminal is an electronic device used to process credit card payments.
protocolA convention that specifies the format of data messages communicated between devices.
prox cardProximity Card. Prox cards are microchip-embedded smart cards that can be read without inserting it into a reader device, unlike earlier mag-stripe cards and contact-type smart cards. Prox cards are a contactless card technology.
prox reader

Proximity Reader. Prox readers provide the convenience of contactless facility access. Prox readers work by continuously emitting a low energy, fixed radio frequency (RF) field that energizes a microchip embedded in the prox card. When the prox card is held within the read range of the prox reader, the RF field is absorbed by a small coil inside the card that powers the embedded microchip, which then transmits a Unique Identification Code (UIC) to the reader.

PTSPIN Transaction Security. A set of security standards applied to secure devices such as the credit card readers.
PXEPre-boot Execution Environment. A means to boot computers without hard drives from a network.

QR codeQuick Response code. A barcode is a machine-readable optical label that contains information about the item to which it is attached. A machine-readable code consisting of an array of black and white squares, typically used for storing URLs or other information for reading by a camera on a smartphone. Some sources use the terms “2D barcode” and “QR code” interchangeably. While QR codes are a type of 2D barcode, not all 2D barcodes are QR codes.


RAIDRedundant Array of Independent Disks. A type of data storage virtualization technology that lumps physical disk drive components together to provide data redundancy and/or performance. A RAID controller is a card or chip located between the Operating System and the storage drives, usually hard disk drives or solid-state drives (SSDs), so that they work together to improve data security and data storage performance.
RDBMSRelational Database Management System. A database management system based on the relational model, which in turn is based on two branches of applied mathematics: set theory and predicate logic.
Receipt Printer ReaderA reader designed to be installed in an exit lane on a pedestal and includes a receipt printer for mag-stripe credit card applications.  Technology is dependent upon the requirements of the facility, and in addition to the mag-stripe credit card reader, may include one or more of the following:  linear barcode, proximity and/or AVI, in addition to options for messaging display and intercom.

Read-Escrow-Print-Mechanism. REPM is a 2D barcode write/read ticketing mechanism for all OPUS devices. mechanism. It's primary functions are to print barcodes using a thermal printhead and to read barcodes with a 2D imager. On the ticketing side it prints, cuts and presents a parking ticket to the customer. On the receiving side, it scans and vaults the ticket.

REST, RESTfulRepresentational State Transfer. An application programming interface (API or web API) that conforms to the constraints of REST architectural style and allows for interaction with RESTful web services. Also known as RESTful API.
RFIDRadio Frequency Identification. An automatic identification method that relies on storing and remotely retrieving data using devices called RFID tags or transponders. RFID is used mainly in access and revenue control facilities and is another form of permit.
RoHSRestriction of Hazardous Substances. RoHS, also known as Directive 2002/95/EC, originated in the European Union and restricts the use of specific hazardous materials found in electrical and electronic products. Organizations often prove RoHS compliance with a letter of compliance issued by an employee of the company.
RS-232A serial data exchange design standard and communications protocol.
RS-485A standard defining the electrical characteristics of drivers and receivers used in serial communications systems.
RTSRequest-to-Send. A signal between computers that indicates that data transmission by an initiating device is requested.
RTVRoom Temperature Vulcanizing silicone sealant. A sealant that begins curing as soon as it is exposed to moisture or air.
RWPVRead-Write-Print-Vault. RWPV is the magcode write/read ticketing mechanism for AMG devices. On the ticketing side it prints, encodes and presents a parking ticket to the customer. On the receiving side, it scans and vaults the ticket.


saltedSalt is random encrypted data used as an additional input to a one-way function that "hashes" data, such as a PAN, a password or a passphrase. Salts defend against dictionary attacks or against their hashed equivalent, a precomputed rainbow table attack.
SaaSSoftware-as-a-Service. A method of software delivery and licensing in which software is accessed online via a subscription, rather than purchased and installed on individual computers. Some SaaS software, such as Symphony Analytics, is hosted in the cloud. Cloud-delivered SaaS software is accessible anytime, anywhere, from any device.
SCRSecure Card Reader. A PTS-approved device that attaches to a mobile phone or tablet for securely accepting payment cards. PCI PTS-approved SCRs protect and encrypt the card data via SRED. See also SRED.
SD cardSecure Digital card. A type of removable memory card used to read and write large quantities of data in a range of mobile digital electronic devices such as cameras, laptops, smart-phones, and more.
SDKSoftware Development Kit. An SDK (or devkit) is typically a set of software development tools that allows the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar operating system platform.
serverA computer that provides services to other computers, such as processing communications, file storage, or accessing a printing facility. Servers include – but are not limited to – web, database, application, authentication, DNS, mail, proxy, and NTP.
SIMSubscriber Identity Module. Also referred to as the Integrated Circuit Card Identifier (ICCID). ICCIDs are stored in the SIM cards and are also engraved or printed on the the card. The number can be up to 19 digits long and contains information about the subscription service (operator), current location, and when it was made. The SIM is used to identify the subscriber with a different unique number, the International Mobile Subscriber Identity (IMSI).
SIPSession Initiation Protocol. Used for controlling multimedia communication sessions like voice and video over IP.
SKPSecure Keypad / Pin-pad. 
SLTSystem Level Test (SLT) – a paradigm shift from traditional structural and functional testing. The device is tested in a complete, integrated system to evaluate its compliance against specified requirements.
smart card

Smart card (banking) is a type of payment card with a built-in IC chip that can be used as credit, direct-debit, or stored-value monetary device that offers counterfeit-proof and tamper-proof transactions. The intelligent microchip on the card – along with smart card readers – use mutual authentication procedures to protect users, merchants, and banks from fraudulent use.

Smart card (access control) is a type of pass card with an integrated circuit card (ICC) owned by an individual or a group used to provide physical access control. When used with a card reader, the card can help authenticate a user looking to gain access.

smart card readerSmart card readers are used with smart cards for electronic processes including personal identification, access control, authentication, and financial transactions.

Subject Matter Expert. A cognizant engineer, developer, technician, etc. who has a deep knowledge of specific technology, designs, processes or functions. An SME is considered an authority on a certain topic – not only educated on the subject matter, but possessing both the authority and capacity to share their knowledge with other interested parties.

SMSShort Message Service. SMS is a text messaging service component of most telephone, Internet, and mobile device systems. It uses standardized communication protocols to enable mobile devices to exchange short text messages. In layman's terms: it's a text message. However, an SMS message contains only text (no pictures or videos) and is limited to 160 characters.
SMTPSimple Mail Transfer Protocol. A push protocol and used to send email messages.
SPISerial Peripheral Interface.
spin-upTo "spin up" a system is to boot up a virtual machine on a computer, or to launch a new server.
SPPMSRSerial Port Power Magstripe Reader. A mag-stripe reader that does not require any external power supply and is compatible with any computer with a serial RS232 interface such as a personal computer (PC), notebook or laptop.
SREDSecure Reading and Exchange of Data. A set of PCI PTS requirements designed to protect and encrypt card data in payment terminals. A PCI Council-listed Point-to-Point Encryption (P2PE) solution must use a PTS-approved and listed payment terminal with SRED enabled and actively performing card data encryption.
SSDSolid State Drive. A type of non-volatile storage media that stores persistent data on solid-state flash memory. Unlike a hard disk drive (HDD), an SSD has no moving parts to break down and no access delay.
SSLSecure Sockets Layer. A global standard security technology that enables encrypted communication between a web browser and a web server. A cryptographic protocol designed to provide communications security over a computer network. A predecessor to TLS.
SSL CertificateCertification that a valid and functioning SSL security protocol is resident on a web server.
SQLStructured Query Language. SQL is a special-purpose programming language designed to communicate with and handle data in a relational database management system.
SQL ServerA database server that provides SQL database services to other programs or computers, as defined by the client-server model.


TDESTriple Data Encryption Standard.
thick client

Also called heavy clients and fat clients – generally defines full-featured computers connected to a network. A thick client is essentially any PC that runs its own programs and may have third-party applications locally installed. A thick client has its own local data storage capability and a full-featured OS. While it requires connection to a central server or network resource, a thick client enables offline users to implement locally installed applications such as MS Word and Excel.

In AMI terminology, the iParcProfessional Parking Management Software is an AMI thick clients that run in the Windows OS environment on a host server or on an application server. The OPUSClient UI to the iParcProfessional PARCS system may include all five functional modules of the PARCS software: Revenue Management, Card Access, Count Monitor, Report Generator and Accounts Receivable. The OPUSClient UI installed on the PARCS server interfaces with any of these modules and is therefore a thick client.

thin client

Also called skinny clients and web clients – generally defines a network computer terminal or device that communicates with a remote server to run server applications and to access information. All features and capabilities typically found on a desktop PC – including local applications, data processing, file storage, direct memory access, etc. – are managed by the remote server and data is stored on the server or in a network data center. Thus, thin clients are functional only when a network connection to the host server is available.

In AMI terminology, the OPUSClient UI thin client (or web client) remotely accesses the iParcProfessional PARCS system software residing on the host server from any location using a remote device with a web browser and Internet connectivity (e.g., a PC, smartphone, or mobile device). The OPUSClient UI thin client is not installed on the remote device; instead, it is accessed over the Internet using a web browser. The OPUSClient UI thin client supports remote device interface only with the Card Access, Count Monitor, and Revenue Management functional modules of the PARCS software. It does not support many of the features of the thick client, including device setup utilities, and access to the Report Generator and Accounts Receivable modules, as well as access to features such as Credential Tracking, Revenue Alarms and 3rd-party application support.

TLSTransport Layer Security. A cryptographic protocol designed with goal of providing data secrecy and data integrity between two communicating applications. It is an IETF standard designed to prevent eavesdropping, tampering and message forgery. TLS is the successor of SSL.
tokenizationA technique used to capture and store credit card data without exposing the merchant to heighted PCI security requirements, or increasing the potential for a data breach. Tokenization also streamlines the automation of credit card transactions.
TCP/IPTransmission Control Protocol/Internet Protocol - a design standard and protocol that governs the connection of computer systems to the internet


Universal Lane ControllerThe primary lane controller that is the connection point between other devices in the parking system including but not limited to the gate controller, access control readers, revenue device inputs and outputs, and general-purpose inputs and outputs.
Universal Reader

Universal Reader with Receipt Printer
A reader with an integrated display designed to be installed in a lane and includes an insert mag-stripe reader for credit cards and FlexScan pocket. The technology is dependent upon the requirements of the facility and may include one or more of the following: proximity, barcode imager, or AVI, as well as options for intercom and pinhole camera.
UPSUninterruptible Power Supply. An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails.
USBUniversal Serial Bus - a design standard and protocol for connecting I/O devices. See also CDC-ACM.
User / UsersAn individual assigned access rights to the parking system hardware and/or software by the site Administrator.


ValidationA store coupon or discount to a parking fee.
ValidatorA device connected to the Fee Computer to read mag-stripe tickets, validation coupons, and credit cards.
Vehicle Loop DetectorAlso, Vehicle Detection Loops and inductive-loop traffic detectors, are electronic sensor circuits that detect vehicles passing over or arriving at a certain point, for instance when entering or exiting a parking lane, approaching at traffic light or metering lane, or in motorway traffic. An insulated, electrically conducting loop and sensor is typically installed in the pavement.
VGAVideo Graphics Array. The standard monitor or display interface array to connect displays to a standard PC's. Although VGA defines the display resolution (e.g., 640 x 480 pixels), it also defines the type of connector used to connect a display to a PC. A range of user-selectable, higher resolutions can be transmitted via the VGA plug using the same 15-pin connector.
VIDUSB Vendor ID. USB Vendor IDs (VID) are 16-bit numbers used to identify a specific USB device manufacturer or provider. Each Vendor ID is assigned by the USB Implementers Forum to a specific company, which in turn assign PIDs to individual products. See also, PID.
Virtual Payment TerminalWeb browser-based access to an acquirer, processor or third-party service provider website to authorize payment card transactions. Unlike physical terminals, virtual payment terminals do not read data directly from a payment card. The merchant manually enters payment card data via the securely connected web browser.
Because payment card transactions are entered manually, virtual payment terminals are typically used instead of physical terminals in merchant environments with low transaction volumes.
VLANVirtual Local Area Network. This is a logical sub-net of a physical network.
VMVirtual Machine.


WANWide Area Network. Fore example, an internet connection using DSL or ISDN.
web clientThe client side of a web application. Web client typically refers to the web browser in a user's machine that runs a client application which communicates with a web server application, such as the MS Outlook mail client. It also refers to a user's machine when running a customer-facing web page within a web server application. It may also refer to plug-ins and helper applications that enable a web browser to support special services provided by the web server.
Webkit engine

An open-source web browser engine that was developed by Apple, Inc. Webkit is the HTML/CSS rendering engine used in the Apple Safari and Google Chrome browsers. Webkit as a term is simply a group of browsers that Safari, Chrome, Opera and iOS browsers fit into. Microsoft Internet Explorer (IE) is an exception, since it does not use the webkit rendering engine.

In CSS, the -webkit- prefix is used for CSS properties not yet officially implemented either by the W3C specifications or by all web browsers, but are available to Webkit browsers. CSS values prefixed with -webkit- are webkit-specific, they're usually CSS3 or other non-standardized features.

WeigandTrade name for a technology used in card readers and sensors, particularly for access control applications. Weigand devices were originally developed by HID Corporation.
wireframeThe skeleton of a planned user interface (UI). A wireframe is a low-fidelity sketch (sometimes literally a pen and paper sketch) of the UI. Wireframes convey the main visual features, functions and content of a UI, without getting into the actual program design.


XON/XOFFProtocol for controlling the flow of data between computers and other devices on an asynchronous serial connection. X/ON and X/OFF are signals to turn a transmitter on or off. The actual signal for X/ON is the same bit configuration as the ASCII Ctrl-Q keyboard combination (11 hexadecimal). The X/OFF signal is the Ctrl-S character (13 hexadecimal).