Eia-485 interface, Red auto/manual signal, Switch cmd signal – Comtech EF Data CSAT-6070 User Manual

Page 90: B.2.2 red auto/manual, B.2.3 switch cmd

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50 Watt C-Band Transceiver

Revision 0

Redundant Systems

MN/CSAT607050.IOM


B.2.1 EIA-485 I

NTERFACE

The RSU-5060 provides a single point interface for the Customers M&C system
by pig tailing the 4-wire EIA-485 input to J5 and passing it out on both the J1 and
J3 interface connectors. When using the EIA-485, 4-wire interface to talk to the
individual CSAT’s are addressed at subsequent addresses through the use of the
‘B SELECT *’ signal going to CSAT B on the J3 interface connector. To set or
change the address of both units, uses the SPA=XXXX command defined in
sections 3 and 4 in conjunction with the global address 0000.

Example: To set the two CSAT’s to addresses 0064 and 0065 send the following
command:
<0000/SPA=0064’cr’

B.2.2 RED AUTO/MANUAL

SIGNAL

Pin P on the J5 connector is the ‘RED AUTO/MANUAL’ input pin. The user can
use this signal to control the operating mode of the RSU-5060. If this pin is left
open, the RSU-5060 is operated in the AUTO mode. In AUTO mode, the RSU-
5060 monitors the state of CSAT A and CSAT B via the ‘A/B FAULT N.O.’
signals on the J1/J3 connectors. If the ONLINE unit fails, the RSU-5060 will
automatically command both the Tx and Rx transfer switches to change position.

Note: If the OFFLINE unit also is FAULTED, no switchover will occur.

The ‘RED AUTO/MANUAL’ signal has a corresponding REMOTE
COMMAND, “RAM=X”. This command, defined in section 4, can be used to
control the operating mode of the RSU-5060 assuming that Pin P is left open.
(Note: Grounding Pin P forces the RSU-5060 into MANUAL mode independent
of the “RAM=X” remote command.

B.2.3 SWITCH CMD

SIGNAL

Pin V on the J5 connector is the ‘SWITCH CMD’ input pin. The user can use this
signal to command the RSU-5060 to change the position of both the Tx and Rx
transfer switches. This pin should normally be left OPEN and momentarily
shorted to ground to force a switch over (minimum pulse width for this signal is
100 mS). The RSU-5060 operating mode does effect how it will respond to the
‘SWITCH CMD’ command.

• If the operating mode is AUTO, a momentary short to ground on Pin V

will cause the RSU-5060 to change the position of the Tx and Rx transfer
switches only if the currently OFFLINE unit is not faulted.

• If the operating mode is MANUAL, a momentary short to ground on Pin

V will always cause the RSU-5060 to change the position of the Tx and

B-8

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