User guide

Hardware Options and Software Licenses
Caution!
The location of the GPS Interface option card is restricted to option card slot 6 (see
Figure 3.1).
If the GPS option card is fitted in a slot other than slot 6 a critical alarm will be raised
to nCompass Control.
3.5.1.2 Connectors
The GPS Interface option card provides dual redundant inputs for 10 MHz and 1
pulse per sec (1PPS) from a GPS receiver. All connectors are located at the rear
panel.
Note: The dual redundant configuration shall be referred to as primary [GPS A]
and secondary [GPS B] inputs.
Figure 3.9 GPS Interface Rear Panel
3.5.1.3 Input Signal Characteristics
The GPS Interface Module accepts signals with the following characteristics:
Table 3.12 GPS Interface (MX8400/HWO/GPS) Pulse Parameters
Input Connector Voltage
Range
Coupling Rise Time Pulse Width
1PPS
50 Ω BNC
+0.8 V to +5.0 V DC coupled 10ns-100ns 100 us – 500 ms
10MHz
50 Ω BNC
+0.3 V to +5.0 V AC coupled sinewave
Indicators are fitted to the interface card back panel to show the status of each input.
Table 3.13 GPS Interface (MX8400/HWO/GPS) Rear Panel Indicators
State Indication Comment
Off No signal Not configured for use
Red Error with input Configured for use
Green Signal present Configured for use
Note: The indicators do not show the MX8400 main reference clock status.
2/1553-FGC 101 1014 Uen B
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