Complete Communications Engineering

Fax Modem Data Modulations & ProtocolsVOCAL’s Fax modem solutions provide a range of fax modulations and protocols for a variety of facsimile applications and fax communications over Internet, radio, mobile, PSTN and other IP networks. Our Super/Group 3 fax softmodem designs include high speed V.34 and V.17 fax as well as T.30 protocol and T.38 fax solutions. Contact us to discuss your fax modem application requirements.

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VOCAL’s fax modem software libraries include support for Super/Group 3 Fax as well as a complete range of ETSI / ITU / IEEE compliant algorithms. Our source code is optimized for performance on ANSI C and leading DSP architectures from TI, ADI, Intel, ARM and other vendors. VOCAL’s fax software may be licensed as a library or part of a complete design with custom solutions available.

supported-platforms

Fax Soft Modem

All of VOCAL’s facsimile modulations and data streams can be controlled with our T.30 protocol functions or with VOCAL’s facsimile service class 1 command sets (EIA-578 and T.31). The T.30 functions could in turn be controlled with VOCAL’s facsimile service class 2 command sets such as T.32 (known as fax class 2.1), EIA-592 (known as fax class 2.0) and industry standard (known as fax class 2). Typical systems can be configured to use T.30 Error Correction Mode (ECM), T.4 copy quality checking/corrections and perform image form conversion for T.4/T.6 and JBIG.

The line interface may be an analog front end (codec and DAA) or a digital interface such as T1/E1, xDSL, ATM, and ISDN. The application interface of this software can support a fax class 2/2.0/2.1 command set or may be used directly by an application.

The fax modem software uses signal detectors to determine the progress of a call by audio means, obtaining user pressed DTMF digits and mode transitioning. The signal detectors and generators include: