0 3 B M Odem Monitor Status; Dmd50 Universal Satellite Modem Mn-Dmd50; Async Port / Es-Es Communications; Internal Clock - Comtech EF Data DMD50 Installation And Operation Manual

DMD50 Universal Satellite Modem
3.3.4 Modem Monitor Status
The modems M&C system is connected to most of the circuitry on any board contained in the
chassis. These connections provide status on the working condition of the circuitry as well as
providing the data required for the various measurements the modem provides. The M&C
processes this information and generates status indications as well as alarms when necessary.
Detailed status information is available via the modems various user interfaces (front panel,
remote and terminal). A summary of this information can be connected to external equipment,
switches or alarms via the open collector and/or form-C fault connections
Form-C Contacts:
The UIM provides three Form-C Relays under processor control that appear at J15.
Mod Fault:
Demod Fault:
Common Fault:
Open Collector Faults:
The UIM provides two Open Collector Faults that appear at Pins 18 & 21 on J19.
Mod Fault:
Demod Fault:
The open collector faults are intended for use in redundancy switch applications in order to
provide quick status indications.
3.4

Async Port / ES-ES Communications

This port is dedicated for ES-ES Communications supported by either RS232 or RS485 signal
levels. The baud rate and protocol can be selected from the Front Panel. The port may be
configured for a number of communications protocols. Overhead data to/from the UIM is routed
to/from the framer/deframer. This port is also used by SCC Framing for the in-band data.
3.5

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, Web Browser or Terminal ports.
MN-DMD50– Revision 3
De-energized when any transmit side fault is detected.
De-energized when any receive side fault is detected.
De-energized when any fault that is not explicitly a Tx or Rx
Fault such as an M&C or Power Supply 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.
Will sink up to 20 ma (maximum) until a receive or common
fault is detected. Will not sink current if a fault is detected.
Theory of Operation
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