At a Glance:
- Robust transmission in 6-wire technology Audio / Data / Power
- Switching-on of up to 48 call stations per Line Interface
- Call station malfunction / identification from the control unit
- Monitoring of call station voltage
- Establishing long-distance lines of up to 13 km (Cable 4 x 2 x 1.2 mm)
- Sending/receiving level can be regulated
- 48V / 72V increased Power Supply
Voice transmission between the call station and DVS-21 is carried out as SOS Line with additional transmission of control and monitoring signals and power feed in 6- wire technology. The audio channel is shared with all SOS Line users.
Each NSA-PL line is secured both by a PTC and a fuse on the front panel. When releasing the fuse, a message will be sent towards CPU1 module, and the “Fuse” LED at the front panel will go out (see chapter “Symbols on the Front Panel”).
The functionality of the AF module can be programmed using the configuration software ICS. Control frames are sent cyclically and bi-directionally over the modem line between the NSA-PL and each WPS-PL call station sequentially. If a subscriber (call station) is absent then an error message is sent to the CPU and the “Sending / Receiving” LED is blinking slowly. This error message can be displayed for instance at a desktop call station DTA or at a PC call station BSA. This monitoring function can be disabled by means of ICS.
Due to long distance power limitation a special Sequential Search Call from the control centre is implemented. After starting a Sequential Search Call each SOS Line User will be announced one after the other automatically.
Interconnection of WPS-PL to NSA-PL
In SOS Line (PL) Application, the overall number of call station depends on the characteristic of the transmission medium, the spacing between the call stations and the operation mode.
Typical values are as follows:
|No. of WPS-PL
|Spacing [m]||Wire diameter [mm]||No. of wires||Max. PL length [km]|
|8 (1/7)||500||0.9||3 x 2||4|
|15 (1/14)||500||0.9||4 x 2||7.5|
|26 (1/25)||500||0.9||3 x 4||12|
|26 (1/25)||500||1.2||4 x 2||13|
The Front Plate Symbols and their Meaning:
|The System Blinker
Addressing from processor taking place
BUS output works as push-push operation with the system blinker
BUS input works as push-pull operation with the system blinker
LED lit: NSA-PL sending to subscriber
LED blinking: NSA-PL receiving from subscriber
LED blinking slowly: Modem connection disrupted
LED on: Fuse OK
|Operating Voltage:||48 V|
|Feeding Current (48V)||2 A|
|Operational Current (+5V)||200 mA|
|Operational Current (-5V)||4 mA|
|Bandwidth:||3.5 kHz / 7 kHz optionally|
|PL Feeding Voltage:||72 V DC|
|Range:||up to 13 km by 1.2 mm 8-wire connection|
|Temperature Range:||0 °C to 45 °C|