asynchronous function A function that allows program execution to continue without waiting for a task to complete. To implement an asynchronous function, an application-defined event handler must be enabled to trap and process the completed event. See synchronous function.
CCITT International Telegraph and Telephone Consultative Committee.
See ITU-T.
configuration file An unformatted ASCII file that stores initialization information for an application.
data structure Programming term for a data element consisting of fields, where each field may have a different type definition and length. A group of data structure elements usually share a common purpose or functionality.
delimiting The ability to return control to the application at the end of each fax page or group of fax pages allowing the application to store these groups into separate files.
ECM Error Correction Mode. An ITU-T T.30 recommendation for Group 4 fax, now also used for Group 3 fax. ECM provides more efficient error handling for noisy or distorted fax transmissions. Encapsulated data within HDLC frames gives the receiver an opportunity to check for and request retransmission of garbled data.
extended attribute functions Class of functions that take one input parameter (a valid Dialogic device handle) and return device-specific information. For instance, a voice device's extended attribute function returns information specific to the voice devices. Extended attribute function names are case-sensitive and must be in capital letters. The fax extended attribute functions return information specific to fax resources. See also Standard Runtime Library.
facsimile Fax. Transmitting and recording a scanned document to produce a copy of the original via phone lines.
fax See facsimile.
fax extended attribute functions See extended attribute functions.
fax session A fax session refers to the five phases of a fax call as defined by the ITU-T T.30 recommendation. The phases are Phase A (set up fax call), Phase B (pre-message procedure), Phase C (transmit message), Phase D (post-message procedure) and Phase E (release fax call).
Group 3 T.4 standards recommendations for digital facsimile devices developed by CCITT, adopted in 1980, and modified in 1984 and 1988. A Group 3 digital fax transmission of an 8.5 by 11 inch page (or A4) at 9,600 bps is completed in 15 to 30 seconds using PSTN phone lines.
Group 4 T.6 standards recommendations for digital facsimile devices developed by CCITT and adopted in 1984. Using Public Data Networks or modified PSTN, the data is transmitted using ECM (Error Correction Mode) which essentially ensures error-free reception.
ID Refers to the telephone number of the fax. As per the ITU-T T.30 recommendations, the information to be included in the local ID 20-character data fields is the international telephone number with + in position 1, followed by the telephone country code, area code and the subscriber number.
ITU-T (formerly CCITT) International Telecommunication Union-Telecommunications. A United Nations agency based in Geneva whose three main aims are developing and recommending international telecommunications standards, regulating the use of radio frequency spectrum, and advancing telecommunications development around the world.
Modified Huffman (MH) code One-dimensional run length digital encoding scheme used to compress fax data for transmission in Group 3 fax devices. For example, a white line with no text, called a run, extending across an 8.5" page equals 1728 bits. MH code compresses the 1728 bits into a 17-bit code word. The lengths for all possible white runs are grouped together into 92 binary codes that will handle any white run length from 0 to 1728.
Modified Modified Read (MMR) code An optional, Group 4 facsimile two-dimensional digital encoding scheme with improved transfer speed over Modified Read encoding. This encoding scheme is now available on Group 3 fax devices. MMR makes use of the high degree of vertical correlation between each scan line in the fax image to achieve a higher compression than MH.
Modified Read (MR) code An optional, Group 3 facsimile two-dimensional digital encoding scheme with improved transfer speed over Modified Huffman encoding. MR makes use of the high degree of vertical correlation between each scan line in the fax image to achieve a higher compression than MH.
normal fax transmission A fax document transmitted from the called to caller application, as in the transmission of a fax document between two fax machines.
pel Picture element containing black and white information. A single point in a facsimile transmission.
Phase A One of five phases in a fax call, as defined by the T.30 protocol recommendation. This is the fax call setup phase; communication is established between two stations, caller and called.
Phase B One of five phases in a fax call, as defined by the T.30 protocol recommendation. This is the pre-message procedure phase of a fax call. The two stations (caller and called) negotiate parameters for a fax transfer, such as receiver and transmitter state, transmission speed, resolution and so on.
Phase C One of five phases in a fax call, as defined by the T.30 protocol recommendation. This is the message transmission phase of a fax call. Transmits based on the parameters negotiated in Phase B.
Phase D One of five phases in a fax call, as defined by the T.30 protocol recommendation. This is the post-message procedure of a fax call where the Phase D continuation value indicates how the data just transmitted is connected to the next data transmitted.
Phase E One of five phases in a fax call, as defined by the T.30 protocol recommendation. This is the fax call release phase: disconnect call.
pixel Picture element containing levels of gray information. A single point in a facsimile transmission.
polling fax transmission Also known as fax on demand. A caller application requests that a fax be transmitted from the called to caller application. If polling is valid, the caller and called applications switch transmitter and receiver roles. The fax is then transmitted from called to caller application.
PSTN Public Switched Telephone Network.
raw fax data Unstructured fax data that does not conform to TIFF/F or other formats. A raw file stores fax data as a single page of unstructured, unformatted data. The raw file uses MH coding for transmission.
SCbus Signal Computing Bus. Third generation TDM (Time Division Multiplexed) resource sharing bus that allows information to be transmitted and received among resources over multiple data lines.
SpringWare Software algorithms built into the downloadable firmware that provides the voice processing features available on all Dialogic voice boards.
SRL See Standard Runtime Library.
standard attribute functions Class of functions that take one input parameter (a valid Dialogic device handle) and return generic information about the device. For instance, standard attribute functions return IRQ and error information for all device types. Standard attribute function names are case-sensitive and must be written in uppercase letters. Standard attribute functions for all Dialogic devices are contained in the Dialogic SRL. See Standard Runtime Library.
Standard Runtime Library A Dialogic software resource containing event management and standard attribute functions, and data structures used by all Dialogic devices, but which return data unique to the device. See the Voice Software Reference - Standard Runtime Library.
stand-alone configuration A hardware configuration where a single board contains all the hardware components (i.e., processing, data reception/transmission) necessary to implement an application. In a stand-alone configuration, the board's channels are not routed through SCbus time slots. NOTE: Some Dialogic hardware products can be used in a stand-alone configuration, or as a component in an SCbus bus configuration.
subaddress A T.30 message protocol that allows a fax to be routed to one or more telephone numbers (or extensions) once it is received by the fax station.
sub-page addressing A method in which a single page of fax data is formed from images stored in different sources. Each stored image is considered a sub-page.
synchronous function A function that blocks program execution until a value is returned by the device. Also called a blocking function. See asynchronous function.
T.30 An ITU-T recommendation that specifies a fax communications protocol for Group 3 fax. This recommendation describes how to establish and terminate communications between Group 3 fax machines. The five phases of a fax session are Phase A, Phase B, Phase C, Phase D and Phase E.
TIFF/F Tagged Image File Format Class F. TIFF is a tag-based general purpose raster format used to exchange image data between application programs. Class F indicates specific format information for fax applications.
time out In telephone networks, an event which occurs at the end of a predetermined interval of time.
turnaround polling fax transmission At different times during a single fax call, the caller and called applications switch transmitter and receiver roles to enable both applications to send and receive a fax document during the fax call.
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