Section 2 Standard Nema Functions; Conflict Monitoring; Red Fail Monitoring; Red Enable Input - EDI SSM-LE Series Operation Manual

SSM-LE Series
Operations Manual
Section 2
Standard NEMA Functions

2.1 CONFLICT MONITORING

When voltages on any conflicting channels are sensed as active for more than the Conflict
Fault time (7.4), the SSM-LE Series will enter the fault mode, transfer the OUTPUT relay
contacts to the Fault position, and display the CONFLICT status screen. The SSM-LE
Series will remain in the fault mode until the unit is reset by the RESET button or the
EXTERNAL RESET input. When voltages on any conflicting channels are sensed as active
for less than the Conflict No-Fault time, the SSM-LE Series will not transfer the OUTPUT
relay contacts to the Fault position.
The SSM-LE Series is fully programmable and requires the use of soldered wire jumpers
on an interchangeable Programming Card to define permissive channel pairs. See Section
5.1 for Programming Card details.

2.2 RED FAIL MONITORING

When voltages on all inputs (G, Y, R, W) to a channel are sensed as inactive for more than
the Red Fail Fault time (7.4), the SSM-LE Series will enter the fault mode, transfer the
OUTPUT relay contacts to the Fault position, and display the RED FAIL status screen. The
SSM-LE Series will remain in the fault mode until the unit is reset by the RESET button or
the EXTERNAL RESET input. When voltages on all inputs to a channel are sensed as
inactive for less than the Red Fail No-Fault time, the SSM-LE Series will not transfer the
OUTPUT relay contacts to the Fault position.
Red Fail Monitoring will be disabled when the RED ENABLE input is not active.

2.2.1 RED ENABLE INPUT

The RED ENABLE input will be sensed as active by the SSM-LE Series when it exceeds
the Red Enable Input threshold (Section 7.1.2). The presence of the proper operating
voltage at this input enables Red Fail Monitoring, Minimum Yellow Clearance Monitoring,
and Dual Indication Monitoring.
The main status screen will display "RE OFF" if the RED ENABLE input is not active.

2.2.2 WALK DISABLE OPTION

This option will modify the operation of Red Fail and Dual Indication Monitoring. When
enabled, the Red Fail and Dual Indication Monitoring function will not monitor the Walk field
outputs. Absence of signals on the Green, Yellow, and Red field outputs of a channel will
place the SSM-LE Series into the Red Fail fault mode causing the Output relay contacts to
transfer. Presence of active signals on the Walk outputs will not cause a Dual Indication
when concurrent with active Red or Yellow signals. This function is enabled by the Option
Switch called "WALK DISABLE". See Section 5.4.4.

2.3 DC VOLTAGE MONITORING

2.3.1 +24VDC SUPPLY MONITORING

The +24V MONITOR I and +24V MONITOR II inputs are provided for monitoring two
+24Vdc supplies in the cabinet assembly. Should loss of proper voltage occur at either of
these inputs, the SSM-LE Series will enter the fault mode, transfer the OUTPUT relay
contacts to the Fault position, and display the appropriate 24V-1 or 24V-2 status screen.
The SSM-LE Series will automatically reset the OUTPUT relay when the correct input
voltages are restored to both of these inputs. The SSM-LE Series will remain in the fault
mode for at least the time determined by the Minimum Flash programming.
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