3 internal clock – Comtech EF Data DMDVR20 LBST Rev 1.1 User Manual
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DMDVR20 LBST Satellite Modem
Theory of Operation
TM136 – Rev. 1.1
3-7
Form-C Contacts:
The UIM provides three Form-C Relays under processor control that appear at J15.
Mod Fault:
De-energized when any transmit side fault is detected.
Demod Fault:
De-energized when any receive side fault is detected.
Common Fault:
De-energized when any fault that is not explicitly a Tx or
Rx Fault such as an M&C or Power Supply Fault.
Open Collector Faults:
The UIM provides two Open Collector Faults that appear at Pins 18 & 21 on J19.
Mod Fault:
Will sink up to 20 ma (maximum) until a transmit or
common fault is detected. Will not sink current if a fault
is detected.
Demod Fault:
Will sink up to 20 ma (maximum) until a receive or
common fault is detected. Will not sink current if a fault
is detected.
The open collector faults are intended for use in redundancy switch applications in order to
provide quick status indications.
3.3 Internal Clock
The time and date is kept in order to ‘time-tag’ system events. User can change the Internal
Clock via the front panel or Terminal ports.