Super Systems 20PQ - Manual (Page 141)

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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.
NOTE: if, when a program is running, a fault condition on the
main input is detected, it has no effect on the program execution
and on the timer events.
d) When “SF.Cn” [C.G09] is set to “Undr”
d.1) if an underrange condition is detected, the power output
is forced to the safety value “SF.UL” [C.G10]
d.2) if an overrange condition is detected the instrument will
operate as described at point a.1).
NOTE: IN ALL CASES ABOVE DESCRIBED THE OUTPUTS
WILL BE FURTHER INFLUENCED BY “OUTPUT CONDITION-
ING”
When servomotor open loop is configured, the “Condition for
output safety value” ("SF.Cn [C.G09]) acts as described below:
1) When “SF.Cn” [C.G09] 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.G09] 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.G09] 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
XKP-1-C2.p65 10/30/01, 9:37 AM 137