User's Manual

3-51
RCVR Capacity Key Mismatch – Part numbers of capacity keys on A and B RCVRs are
different.
A/B Tx OVERRIDE – A or B XMTR has been switched and locked in-service using controls
on the front panel of the controller module. Online XMTR will not switch out-of-service
regardless of alarms.
A/B Rx OVERRIDE – A or B RCVR has been switched and locked in-service using controls
on the front panel of the controller module. Online RCVR will not switch out-of-service
regardless of alarms.
A/B I/O OVERRIDE – A or B I/O interface has been switched and locked in-service using
controls on the front panel of the controller module. Online I/O interface will not switch
out-of-service regardless of alarms.
3.17.6 Relay Control Outputs
Control outputs and control status inputs operate together to perform
control functions. The control status inputs to the relay interface must
be properly wired to the external equipment that is being controlled by
the associated control output in order to display the ON or OFF status
on the USI control screen. Without the control status inputs, the control
function on the USI screen will still turn on equipment/functions, but
no status will be indicated and, once turned on, the equipment/func-
tion cannot be turned off.
Six relay control outputs (CTRL 1-6) provide relay closure to ground (provisioned NC) or
open (provisioned NO) when activated. These relays default to open if card power is lost.
The maximum contact rating for each relay is 0.5 A, 100 Vdc.
Nine buffered status inputs (CTRL STATUS 1-6) from the equipment controlled by the
CTRL 1-6 outputs, verifying the controlled function. The inputs are diode protected from
voltages outside of the 0 to +5 V range, and have a 10K Ohm resistor for current limiting
purposes. In addition, each input has a 100K Ohm pull-up resistor.
Note