MXD5U OPERATIONS AND MAINTENANCE
RS_TXErr
11
Status,
Transmitter
Error
Ground
Reference
12
Ground
Reference
RT_RflPwr
13
Telemetry,
Reflected
Power
RT_AGC 14
Telemetry,
AGC
Voltage
(1/2
Scale)
Ext1+
15
External
Interlock, (+12V Armed)
2.5 E
XTERNAL
T
RANSMITTER
I
NTERLOCK
The transmitter provides the customer a set of contacts where an external interlock can be applied to control the
ON state of the transmitter. The purpose of this interlock is to shut down the transmitter if there is sensed an
emergency condition (such as a building fire or smoke alarm) or it there is some RF output switch that is going to
be moved and the RF output of the transmitter needs to be shut off temporarily when the switch is in transit. If
there is no application for this interlock then the customer must insure that it is shorted out (i.e., closed) so that
the transmitter is enabled to be turned ON.
The external1 interlock contacts are available in two separate locations. The first location is on the two pin terminal
block on the rear of the transmitter chassis. This is the more likely and convenient place for the External1 interlock
to be connected. A second parallel set of contacts is located on the 15-pin Telemetry D-connector on the rear of the
transmitter chassis. Only one set of these contacts need to be closed to enable the transmitter since they are in
parallel.
These pins would expect a dry contact that is closed when there is no error condition. This External #1 interlock is in
parallel with the two pin terminal block on the rear of the transmitter chassis. The transmitter applied its own +12V to
one side of this interlock (the Ext1+ line) and will sense this +12V on the other interlock side (the Ext1- line).
PUB09-03 Rev 0 April 16, 2009
09-03-8
MXD5U Operations and Maintenance
