Dialogic SCBus Overview - Voice C++ SDK/ActiveX 

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The SCBus is a real-time, high-speed, time division multiplexed communications bus that provides 1024 time slots for transmission of digital information between Dialogic SCBus products.  The SCBus allows high-density systems to efficiently share resources so that multiple technologies can be connected to each port as needed.

Every Dialogic SCBus product consists of several devices.  Each of these devices can communicate, via the SCBus, with any other device connected to the SCBus.  For example:

·         a D/41ESC board provides 4 on-board analog loop start line interface devices and 4 voice devices for a total of 8 devices communicating over the SCBus.

·         a D/160SC-LS board provides 16 on-board analog line interface devices and 16 voice devices for a total of 32 devices communicating over the SCBus.

·         a D/240SC-T1 board provides 24 digital line interfaces and 24 voice devices for a total of 48 devices communicating over the SCBus.

·         a D/300SC-E1 board provides 30 digital line interfaces and 30 voice devices for a total of 60 devices communicating over the SCBus.

·         a VFX/40ESC board provides 4 on-board analog line interface devices and 4 FAX/voice devices for a total of 8 devices communicating over the SCBus.

SCbus resources

All devices connected to the SCBus have a transmit channel and a receive (listen) channel.  At system initialisation, each transmit channel is assigned to a specific and unique SCBus time slot.  This transmit channel assignment cannot be changed by the application.

All transmit channels are pre-assigned. As a result, routing an SCBus device only requires connecting the receive (listen) channel of the device to an SCBus time slot.  The connected device will then listen to all data transmitted over that SCBus time slot.  This receive channel can be moved (disconnected and connected) to a different SCBus time slot at any time by the application.
Voice C++ supports the following  SCBus resource types:

Digital and analog line interface resources

Line interface resources connect to the telephone network. Depending on the type of phone line used, line interface resources can be analog or digital. Analog line interfaces connect to regular analog  phone lines. Digital line interfaces connect to T1, E1 or ISDN digital telephone networks.

When the application opens a line interface resource, it has to specify the type of  phone line that is connected to the board.  In addition, for T1 and E1 lines, the protocol that should be used must also be specified.

Voice C++ currently supports Analog, T1 robbed bit, E1 CAS and ISDN PRI lines. All of these line types are supported by Voice C++ through the Dialogic Global Call API.  Therefore, the Global Call API should be installed and configured correctly.

Both analog and digital line interface resources provide services like dialing a phone number, waiting  for incoming calls, answering a call and disconnecting a call.

In most cases, all of these tasks can be performed by only using line interface devices; however sometimes the line interface resource also needs a voice resource to complete these tasks.

Digital line interfaces connected to T1 or E1 lines require a voice resource in order to dial a phone number.
For voice boards with on-board analog devices (D/41ESC, D/160SC-LS and VFX/40ESC boards), a voice device and an analog line interface device comprise a single channel.  Although these resources can be addressed separately, all analog signaling is processed by the associated voice device and analog signaling (ring detection and loop current detection) events are not transmitted over the SCBus. This means that analog line interface devices need the associated voice device in order to perform these operations.

Voice devices on analog loop-start interface boards and their associated analog line interfaces can be used separately; however they should be used mutually exclusively.

When a D/41ESC or a VFX/40ESC board is configured as a resource device, the analog devices on that board will be disabled.  This configuration is typically used for fax or voice sharing applications.

Voice C++ names analog line interface resources as dxxxB1C1, dxxxB1C2, … and digital line interface resources as dxxxB1T1, dxxxB2T2, …

Voice resources

Voice resources perform operations like signal detection, voice recording, voice playing, DTMF detection and tone generation. Voice resources do not need other resources to perform these tasks; however the caller (or person being called) will not be able to notice these actions without connecting the voice resource to a line interface resource.

Voice C++ names voice resources as dxxxB1C1, dxxxB1C2, …

Fax resources

Fax resources handle fax transmissions. Applications should use these resources to send and receive fax documents. In order to perform a fax operation, the application should call a remote fax machine using line interface resources. When the call is connected, the application should connect the line interface resource to an available fax resource. When the fax has been sent, the application disconnects the fax resource from the line interface resource and hangs up the line.

Voice C++ currently supports two types of fax devices:

·         Dialogic VFX series analog voice/fax boards.

·         SCBus compatible GammaLink fax boards (i.e. CP-4/SC, CP-6/SC, CP-12/SC).

For  GammaLink fax devices, the GammaLink Development Kit (GDK) should be installed and the board should be configured to work in SCBus mode.

Voice C++ names VFX series voice resources as dxxxB1C1, dxxxB1C2, … and GammaLink fax resources as Channel0, Channel1, …

Voice C++ SCbus support overview

Supported hardware

Voice  C++ supports the full range of Dialogic SCBus compatible voice and fax boards, analog and digital line interface boards and SCBus compatible GammaLink fax resource boards.

Voice C++ is also compatible with Dialogic’s non SCBus compatible voice boards like the D41H and Dialog/4, but these boards will not be able to communicate with other devices through the SCBus.

Software requirements

Voice C++ supports Dialogic’s System Release 5 (SR5) drivers. The following SR5 components should be installed for Voice C++ to work correctly:

  • ·         The Dialogic drivers and runtime environment.

  • ·         Global Call API and Global Call protocols.

  • ·         The Dialogic system service should be running.

  • ·         If there are GammaLink boards in the system, the GDK should also be installed and the GammaLink system service running.

All the above components are part of  SR5 and they can be selected when SR5 is installed.

To obtain SR5, please contact Dialogic for a CD or go to support.dialogic.com and download the drivers.

Click here to Download the Voice C++ demo: