4. Function Overview

• 4.1.1. Alarm Functions
• 4.1.2. Diagnostic Functions
• 4.1.3. Extended Attribute Functions
• 4.1.4. Parameter Request Functions
• 4.1.5. Parameter Setting Functions
• 4.1.6. Resource Management Functions
• 4.1.7. Routing Functions
• 4.1.8. Time Slot Audio Functions
• 4.1.9. Time Slot Signaling Functions
  

4.1. Digital Network Interface Function Categories

This chapter describes the Digital Network Interface library functions that control the Digital Network Interface hardware. A complete reference describing these functions in detail is located in Chapter 5. Function Reference.

The Digital Network Interface library functions provide the necessary building blocks to create voice applications using T-1 or E-1 lines. These functions can be divided into the following categories:

• Alarm functions - control T-1 or E-1 alarm handling
• Diagnostic functions - test Digital Network Interface hardware
• Extended Attribute functions - retrieve device-specific attribute data
• Parameter Request functions - request device parameters
• Parameter Setting functions - set device parameters
• Resource Management functions - open and close Digital Network Interface devices
• Routing functions - generate communication between devices connected to time slots
• Time Slot Audio functions - generate audio signals on time slots
• Time Slot Signaling functions - alter signaling portion of time slot

NOTE:

Many Digital Network Interface library functions can operate in either synchronous mode or asynchronous mode. Synchronous functions do not return control to the calling process until the function call is completed. To operate a function in asynchronous mode, your application must include an event handler to trap and process the completion event.

Each category and its functions are briefly described in the following sections.

4.1.1. Alarm Functions

• dt_setalrm( ) - set alarm handling mode
• dt_xmitalrm( ) - start/stop alarm transmission

The Alarm functions allow your application to control the way T-1 or E-1 alarms are handled. The dt_setalrm( ) function sets the alarm-handling mode. The dt_xmitalrm( ) function starts and stops the transmission of alarms.

For a detailed discussion of T-1 and E-1 alarm handling, refer to Chapter 3. Digital Telephony Overview.

4.1.2. Diagnostic Functions

• dt_rundiag( ) - run diagnostics on Network firmware
• dt_tstcom( ) - test board Interface communications
• dt_tstdat( ) - run data test on board device

The Diagnostic functions check the Network firmware and hardware. The dt_rundiag( ) function runs diagnostics on the Network firmware and the other two functions test the hardware. The dt_tstcom( ) function tests communication between the PC and the Digital Network Interface device. The dt_tstdat( ) function tests the reliability of data transfer between the PC and the Digital Network Interface device.

4.1.3. Extended Attribute Functions

• ATDT_BDMODE( ) - board signaling mode (all time slots)
• ATDT_BDSGBIT( ) - board signaling bits (all time slots)
• ATDT_DNLDVER( ) - downloaded Network firmware version
• ATDT_IDLEST( ) - time slot idling state
• ATDT_ROMVER( ) - EPROM version
• ATDT_STATUS( ) - time slot status
• ATDT_TSMODE( ) - get time slot signaling mode
• ATDT_TSSGBIT( ) - get time slot signaling bits

Standard Attribute functions, which are contained in the Standard Runtime Library (SRL, see Appendix A - Standard Runtime Library), provide generic information about a device, such as its name or the status of the last function call of the device. Extended Attribute functions return device specific information. The Digital Network Interface library Extended Attribute functions return information about Digital Network Interface logical board and time slot devices.

Extended Attribute function error handling is similar to that of other Digital Network Interface library functions. Most Extended Attribute functions return AT_FAILURE on error. One Extended Attribute function, ATDT_BDSGBIT( ), returns the value AT_FAILUREP on error. Refer to Section 4.2. Error Handling for information about retrieving errors.

4.1.4. Parameter Request Functions

• dt_getparm( ) - get device parameter
• dt_getevt( ) - blocks and returns control after event
• dt_getevtmsk( ) - get device event bitmask

Parameter Request functions are used to check the status of Network parameter and event mask settings.

4.1.5. Parameter Setting Functions

• dt_setparm( ) - change device parameter
• dt_setevtmsk( ) - change device event mask

The Parameter Setting functions set Network device parameters and masks used for event management.

4.1.6. Resource Management Functions

• dt_open( ) - open board or time slot device
• dt_close( ) - close board or time slot device

Resource Management functions open and close devices. Before you can perform an operation on a device, the device must be opened. The dt_open( ) function returns a unique device handle. All subsequent operations on the device must use this handle.

NOTES:

NOTES: 1. A device handle is NOT the same as a system file handle.

2. Opening or closing a Digital Network Interface device does not affect other processes using the device. (See Chapter 6. Application Guidelines, for more information on opening and using DTI devices.)

3. The value returned by dt_open( ) for a Digital Network Interface logical board is referred to as a logical board device handle in this guide.

4.1.7. Routing Functions

Refer to the SCbus Routing Function Reference for more information about these functions.

• dt_getctinfo( ) - get information about the Digital Network Interface time slot device connected to the SCbus
• dt_getxmitslot( ) - returns SCbus time slot connected to the digital network interface time slot device
• dt_listen( ) - connects the receive of a Digital Network Interface time slot device to an SCbus time slot
• dt_unlisten( ) - disconnects the receive of a Digital Network Interface time slot device from an SCbus time slot

Routing functions enable the application to make or break a connection between voice, telephone network interface and other resource channels connected via SCbus time slots.

4.1.8. Time Slot Audio Functions

• dt_setidle( ) - enable/disable time slot idle state

A Time Slot Audio function affects only the transmitted audio portion of a time slot. It replaces the normal voice data on the audio portion of a time slot with other data. The dt_setidle( ) function transmits an idle pattern (digital equivalent of silence) on the selected Digital Network Interface time slot. The specific idle pattern transmitted can be specified via the download configuration file or by using the dt_setparm( ) function.

4.1.9. Time Slot Signaling Functions

• dt_dial( ) - dial a pulse digit string
• dt_setsigmod( ) - change time slot transmit signaling mode
• dt_settssig( ) - change time slot signaling bits
• dt_settssigsim( ) - clear and set signaling bits simultaneously
• dt_xmitwink( ) - transmit wink signaling

Time Slot Signaling functions affect the transmitted signaling portion of a time slot. The dt_setsigmod( ) function selects the origin of the signaling information. The signaling information can either be inserted by the Digital Network Interface hardware or derived (by way of the SCbus) from an SCbus compatible resource device (such as a D/240SC-T1) or another network device. The dt_settssig( ) function sets the state of the signaling bits when the signaling information is inserted by the Digital Network Interface board (signaling insertion mode). The dt_xmitwink( ) function transmits wink signaling to the network on any of the available signaling bits (for T-1, bit A or B; for E-1, bit A, B, C, or D).

NOTES:

1. The signaling bit and polarity used for wink signaling are only configurable through the download parameter file. See the Software Installation Guide (for Linux or Windows) for details.

2. If your configuration includes Voice boards, you can use the Voice library function dx_dial( ) instead.

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