2.4.1 DC and data connector

The Alarm and data connectors of the sat-nms LFTRX chassis are located at the front side of the enclosure up right. The figure below illustrates the location of the connectors and the pin out.

To meet mentioned EMC standards, use double shielded twisted pair CAT7 S/FTP Network cable, e.g. DRAKA UC900 SS27 Cat.7 PUR, for connecting network, serial and alarm interfaces. Ensure that the shield is connected properly.

DC Power Supply

The unit needs 9..24V DC at the corresponding pins of this interface. The LED PS shows the presence of the power supply.

Alarm

Open collector contacts represent a fault state of the unit. With solder jumper SJ1 and SJ2 the polarity of the alarm interface can be chosen (NC or NO at Alarm). The LED LD shows the status of the Laser Diode Alarm (green light means current is in the current limt range (10 to 45.5mA). The LED PD shows the status of the PIN Diode Alarm (green light means the optical level is above 220uW).

Monitoring

The laser diode (tx) monitoring point shows the actual laser diode current. 100mV relates to 10mA laser current against GND. The pin diode (rx) monitoring point shows the actual optical receive level. 100mV relates to 100uW optical input power against GND.

DC interface pin out

Pin Alarm contacts (DSUB-9 male) Description
1 NC not connected
2 NC not connected
3 NC not connected
4 +9..24V / 260mA@12V Power Supply Input. te .ts 5
7 TX Alarm Open Collector max. 24VDC/50mA
8 RX Optical Monitor 100uW = 100mV
9 RX Alarm Open Collector max. 24VDC/50mA