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
4
–
–
SITRANS T3K PA
C79000-B7174-C55-04