Status On The Measured Value Status; Open Circuit Monitoring With Short-Circuit Monitoring - Siemens SITRANS T3K PA Instruction Manual

7NG3213
3.2

Status on the measured value status

Sensor cables and electronic circuits of the measuring instrument are
continuously monitored. The status information is adapted accordingly
in the case of a fault (see chapter 1.3, page 64).
3.3 Open circuit monitoring with short-circuit
monitoring
The test can be enabled (+ in the following table) or disabled (– in the following
table) by a PA parameter which enables a channel-related check for open circuit
and short-circuit.
The following combinations are possible:
(channel assignment see Figure 5, page 85)
Parameter code
Open circuit
Short-circuit
+
–
semibold
Note on open circuit check:
If there is a open circuit, no reference temperature of the internal sensor
(electronic temperature) can be determined.
Note on short-circuit check:
3 Ω is used as a threshold value for the short-circuit check. A line resistance
below3 Ω is interpreted as a short-circuit insofar as no sensor resistance is avail-
able. There is no short-circuit check in thermocouples and millivolt transmitter.
90
Channel 1
0 1 2
+ + –
+ – +
Check enabled
Check disabled
normal state
Channel 2
3 0 1 2
– + + –
– + – +
Instruction Manual
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SITRANS T3K PA
C79000-B7174-C55-04