User's Manual

SDB680 – INSTALLATION GUIDE TNM-I-E-0046

May 15 Page 20 ELECTRICAL CONNECTIONS

S1 Facilities Connector

The 25-way D Type facilities connector can be programmed for any combination of digital inputs and

outputs. The connector pin-outs for the Facilities Connector are shown below in Table 7.

Table 7. Facilities Connector Pin-outs.

Pin Function Pin Function

1 Digital Input 14 Digital Output

2 Digital Input 15 Digital Output

3 Digital Input 16 Digital Output

4 Digital Input 17 Digital Output

5 Digital Input 18 Digital Output

6 Digital Input 19 Digital Output

7 Digital Input 20 Digital Output

8 Digital Input 21 Digital Output

9 GPS Rx + 22 GPS Rx -

10 GPS Tx + 23 GPS Tx -

11 1PPS Rx + 24 1PPS Rx -

Digital to Analogue Converter (DAC)

Output

25 0 V

13 Supply Voltage

Maximum current provided by the supply voltage pin (pin 13) is 1 A protected by a self resetting fuse.

The Digital Outputs are open collector and able to sink 300 mA each; the total for all outputs must not

exceed 600 mA.

Digital inputs are active low. Digital high voltages should not exceed 20 V.

The GPS Rx and 1PPS Rx connections are Differential RS422.

The “Analogue Out” connection is between 0 V and 5 V and software controlled to indicate various

functions e.g. Received Signal Strength Indication (RSSI) level.