PIKA Technical Bulletin #41 V-12 RAN Trunk Interface Implementation Supported by: model V-12 FORMULA with FSB 045 V-12 RAN MODIFICATION External Power supply requirements: -48VDC. RAN trunks are based on a four wire interface, two for balanced audio ( Audio A and B) and two for DC signaling (Control Pulse and SENSE). Although the V-12 software driver does not directly support the various RAN Trunk protocols, applications do have direct access to the signaling leads and can easily implement the desired signaling protocols. V-12 Card Hardware Setup The PIKA V-12 card is equipped with a line interface configuration keys that allow connection recorded announcement (or RAN) trunks. The RAN interface configuration provides play back of digitized audio on a balanced audio line, with an associcated signaling input lead and output lead as shown in the following diagram: V12-RAN PBX AUDIO A AUDIO B AUDIO OUTPUT CP DC PULSE OUTPUT ST DC SENSE INPUT
Telco Line Connections The V-12 RAN analog lines are connected through an RJ-21style connector, with pinout as defined below: SENSE 0 1 26 CP 0 AUDIO_A 0 SENSE 1 AUDIO_A 1 2 3 4 27 28 29 AUDIO_B 0 CP 1 AUDIO_B 1 SENSE 11 23 48 CP 11 AUDIO_A 11 24 49 AUDIO_B 11 25 50 The following table shows in detail the full telco connector pinout for the V-12 RAN: PIN SIGNAL PIN SIGNAL 1 SENSE 0 26 CP 0 2 AUDIO_A 0 27 AUDIO_B 0 3 SENSE 1 28 CP 1 4 AUDIO_A 1 29 AUDIO_B 1 5 SENSE 2 30 CP 2 6 AUDIO_A 2 31 AUDIO_B 2 7 SENSE 3 32 CP 3 8 AUDIO_A 3 33 AUDIO_B 3 9 SENSE 4 34 CP 4 10 AUDIO_A 4 35 AUDIO_B 4 11 SENSE 5 36 CP 5 12 AUDIO_A 5 37 AUDIO_B 5 13 SENSE 6 38 CP 6 14 AUDIO_A 6 39 AUDIO_B 6 15 SENSE 7 40 CP 7 16 AUDIO_A 7 41 AUDIO_B 7 17 SENSE 8 42 CP 8 18 AUDIO_A 8 43 AUDIO_B 8 19 SENSE 9 44 CP 9 20 AUDIO_A 9 45 AUDIO_B 9 21 SENSE 10 46 CP 10 22 AUDIO_A 10 47 AUDIO_B 10 23 SENSE 11 48 CP 11 24 AUDIO_A 11 49 AUDIO_B 11 25 50
The following diagram illustrates the pinout provided by the optional Telco line extender cable and breakout box: 1 2 CP 0 (green) SENSE 0 (red) CP 1 (green) SENSE 1 (red) AUDIO_A 0 AUDIO_B 0 AUDIO_A 1 AUDIO_B 1 12 CP 11 (green) SENSE 11 (red) AUDIO_A 11 AUDIO_B 11 External Power supply Connections An external -48VDC power supply is required to supply and detect RAN signaling voltages. The current requirement for this supply is at least 80mA per line (about 1 Amp per 12 line card). The following diagram illustrates how the power connector must be connected for RAN mode operation: External Power Connector 1 2 3 GROUND -48VDC External Supply V12-RAN
Audio Processing In RAN mode, the V-12 provides audio playback and interface to twelve 600 ohm transformer coupled lines labeled AUDIO A & AUDIO B. The audio lines carry no DC current, ie these are 'DRY' connections. The card supports audio formats including Linear, Ulaw, Alaw, OKI ADPCM (32Kbps, 16 Kbps and 12 Kbps). The V12-RAN audio pairs can be used as 600 ohm direct line level input audio ports for recording audio announcements at system setup time.
CP Line Output Signaling The V-12 RAN provides relay contact closure outputs (CP) for driving GROUND, BATTERY or OPEN signals out to the external system (i.e. PBX or CENTREX). The CP output signal is generated under software control of RELAY 0 of a line circuit. This relay is used to switch the CP output lead for the line between battery and ground. A user selectable jumper HDRAN on the line interface programming key allows the relay to switch between battery and open circuit when removed. The configuration key programs a pair of adjacent circuits on the V-12. The following figure shows the position of the HDRAN jumper on the RAN configuration key. This jumper is removed by cutting the trace with a small knife: HDRAN (first circuit) HDRAN (second circuit) V-12 PIKA These following table shows how V-12 RAN based applications can meet any required interface signaling voltage requirements: RELAY 0 STATE HDRAN CP OUTPUT GENERATED OFF IN BATTERY ON IN GROUND OFF OUT BATTERY ON OUT OPEN
Sense Line Input Supervision The V12-RAN detects DC input signals on its SENSE input lead using an on-board microprocessor and analog to digital converter. The SENSE input supervision circuits have software programmable voltage switching detection thresholds for adapting the card to any type of line conditions. The V-12 RAN SENSE input can detect voltage transitions between BATTERY, GROUND or OPEN signals. This detection capability allows V-12 RAN based applications to meet any required interface sensing voltage requirements. Since OPEN circuit input voltages must be sensed on RAN trunks, an idle state reference voltage must be put on the line by the card. In order to establish the reference voltage for the sense input, RELAY 1 of a line circuit is used. The reference voltage takes on the value shown in the following table when the sense line input is open circuit. When voltage transitions occur on the SENSE line, an event is returned to the application by the V-12 device driver. The following table also shows how to use the supervision capabilities of the V-12 RAN: RELAY 1 STATE REFERENCE (=OPEN CIRCUIT VOLTAGE) INPUT SIGNAL TRANSITIONS DETECTABLE DRIVER EVENT OFF BATTERY OPEN GROUND EVT_LCTERM BATTERY GROUND OPEN EVT_LCPOS ON GROUND BATTERY OPEN EVT_LCTERM GROUND OPEN BATTERY EVT_LCNEG GROUND BATTERY GROUND EVT_LCTERM GROUND GROUND BATTERY EVT_LCNEG
The application uses V-12 API function pika_set_loop_current() to setup the voltage reference point used to determine when the SENSE line has made a transition. For RAN applications, parameter lc_off_threshold must be set to a high value (0xFE). Parameter lc_on_threshold determines the voltage threshold that is used to determine that a voltage transition has occured on the SENSE line. The actual value programmed into lc_off_threshold is given in the following table: lc_on_threshold Equivalent DC Voltage 0x18-10 0x30-20 0x55-30 0x70-40 0x80-50 The following diagram graphicaly illustrates how the SENSE line voltage detection feature works: PROGRAMMED THRESHOLDS 0x00 SENSE Line V oltage Transitions TYPICAL VOLTAGE THRESHOLDS 0Volts lc_on_threshold -10Volts lc off threshold = 0xFE p rog ram m ing lim it 0xFF LCTERM even t LCPOS o r LCNEG even t -70Volts
Controlling V-12 Relays Application programs use a low level API function pika_send_hc11_msg() to directly control Relay 1 and Relay 0 as described here. Syntax #include "pika.h" pika_errors pika_send_hc11_msg ( int ch, char far * msg, int msg_size); Description This function can be used to send, directly from the application, a message to the on-board HC11 microprocessor which controls hookswitch relays and performs voltage supervision. The first byte of all the messages contains the sequence number and it is filled by the driver. Arguments ch msg msg_size channel number; if the message affects all the channels on the board, the first channel of the board should be specified pointer to the message to be sent the total length of the message Return 0 = operation failed because the send queue is full 1 = operation completed successfully Applicable Events No events are applicable to this API, but if the message starts an operation on HC11, the microcontroller will send back a message when the operation is complete. If the channel corresponding to the message is idle, the driver will ignore the response message. If the channel is not idle, the message can interfere with the operation already in progress.
DOS TSR Driver Access AH = PIKA_SEND_HC11_MSG(184) AL = channel. DS:DX = pointer to the message to be sent BX = messaage size Setting a relay using pika_send_hc11_msg() In order to set a relay, a 5 byte message has to be sent. The message has the following structure: typedef struct { byte header; * header and sequence number * byte opcode; * opcode for message => 0x12 * byte pid; * channel on board * byte rid; * relay ID * byte mid; * relay mode ID * } Relay; header opcode - is filled in by the driver - 18 (HC11_SET_RELAY) pid - channel on board, from 0 to 11 Ex: System channel 14 is on board channel 2 rid mid - 0 or 1 (each channel has two relays) - 0 to set the relay ON or 1 to set the relay OFF