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When servomotor open loop is configured, the “Condition for
output safety value” ("SF.Cn [C.G07]) acts as described below:
1) When “SF.Cn” [C.G07] is set to “Cnd.A” and an overrange or
an underrange condition is detected, the servomotor is driven
to its high limit position (OUT 3 “s” will be maintained
closed).
2) With “SF.Cn” [C.G07] is set to “Cnd.b” and an overrange or
an underrange condition is detected, the servomotor is driven
to its low limit position (OUT 4 “t” will be maintained closed).
3) When “SF.Cn” [C.G07] is set to “Cnd.C” the out-of-range
condition acts on the control output as the complement of
effect described at point a).
These instruments are capable to detect, on the main input, the
sensor leads break condition.
When the sensor leads break condition is detected, the
instrument shows “OPEn” on the upper display.
Note: On the linear input the leads break can be detected only
for 4-20 mA, 1-5 V, 2-10 V, 0-60mV and 12-60 mV ranges.
In addition, on RTD input a special test is provided to signal
“Shrt” when input resistance is less than 12 W (Short circuit
sensor detection).
When a fault condition different from overrange or underrange is
detected on the main input, the alarms,the power output and the
analog retransmissions operate as in presence of an overrange
condition.
Xkc-1-C0.P65 5/29/02, 11:59 AM104