The D/42D-SLTM is a PC AT® compatible voice processing board that interfaces directly to SL-1 Line Circuit boards in a Northern Telecom SL-1 PBX. The D/42D-SL emulates four Digit Display electronic telephones. Application programs using the D/42D-SL board can answer incoming calls, place outbound calls, record and playback voice files, detect and generate tones, access the called/calling number ID for calls forwarded or transferred from within the PBX, access trunk ID for calls originating outside the PBX, and control message waiting notification. The D/42D-SL board also provides positive disconnect supervision to immediately detect when a caller has hung up.
When used with the Northern Telecom SL-1, the D/42D-SL board provides a flexible platform for developing integrated computer telephony applications. Dialogic developers can integrate current D/4x applications on the D/42D-SL board with minimal software modifications and create more efficient applications for the PBX by offering value-added features.
A D/42D-SL board has four channels that connect directly to Northern Telecom SL-1 Line Circuit boards in a Northern Telecom SL-1 PBX. The SL-1 Line Circuit boards support Northern Telecom's Digit Display telephone, which has a 16 character display and feature keys for accessing advanced features.
3.4.1. Features3.4.2. Functional DescriptionThe D/42D-SL board connects to line circuit boards that support Northern Telecom's Digit Display Telephone. These telephones have a 16-character display and feature keys for accessing advanced features of the PBX.
Each of four line interfaces on the D/42D-SL board receive analog voice and digital signaling information from the PBX SL-1 line circuit board.
Digital data received from the PBX by the D/42D-SL passes through a digital duplexer to a command format converter where it is converted from SL-1 format to D/41D format. A UART (universal asynchronous receiver/transmitter) then converts this serial bit stream into a parallel bit stream that is sent via the local bus to the control processor which either acts on the information or passes the event to the application - refer to Figure 2.
Figure 2. D/42D-SL Functional Block Diagram
Analog voice signals received by the D/42D-SL pass through a audio duplexer and are converted to digital data by an A/D converter. The raw digital data is then compressed by the DSP and sent to the PC for storage. When sending stored voice data to the PBX, the digital voice data is sent from the PC to the DSP where it is uncompressed. It is then converted back to an analog voice signal by the D/A converter and sent to the PBX via the audio duplexer.
In addition to having all the standard features of a Dialogic D/41D board, the D/42D-SL board can access enhanced PBX features such as:
The D/42D-SL has an on-board microprocessor and a high speed Digital Signal Processor (DSP) to provide voice and call processing. SpringWareTM voice processing firmware is downloaded from the host computer to the microprocessor and DSP when the D/42D-SL board is started. SpringWare offers several features including PerfectPitchTM Speed Control, PerfectLevelTM Volume Control, Global Tone DetectionTM, and Positive Voice DetectionTM. Global Tone Detection allows applications to detect special intercept tones, fax tones, modem tones, non-standard PBX tones, or user-defined tones, such as tones in international networks.
Other DSP-based SpringWare features include variable voice sampling rates of 24 and 32 Kb/s ADPCM, and 48 and 64 Kb/s Mu-law PCM. An application may dynamically switch between sampling rates and coding methods to meet specific requirements for voice quality and data storage. Enhanced algorithms provide reliable DTMF detection, DTMF cut-through, and talk off/play off suppression.
3.4.3. ConfigurationsThe D/42D-SL board connects to a Northern Telecom SL-1 Line Circuit board in a Northern Telecom SL-1 PBX (check specific PBX models and software releases for compatibility) to build sophisticated, computer telephony systems. The D/42D-SL board installs in IBM® PC XT®/AT® (ISA bus) and compatible computers (8088, 80286TM, 80386TM, 80486TM or PentiumTM-based PC platforms). The D/42D-SL board occupies a single expansion slot and up to 16 boards can be configured in a system with each board sharing the same interrupt level. The maximum number of lines that can be supported is dependent on the application, the amount of disk I/O required, and the host computer's CPU.
The D/42D-SL board shares a common hardware and firmware architecture with other Dialogic products for maximum flexibility and scalability. Features can be added or systems can grow while protecting investment in hardware and application code. With only minimum modifications, applications can be easily ported to lower or higher line-density platforms.
3.4.4. Software SupportFor information on other operating system support, contact your Dialogic Sales Engineer. The development package includes all required libraries, drivers and headers for simplified and seamless PBX integration. Diagnostics and demo programs provide additional tools and examples that allow developers to create complex multichannel voice applications.
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