Siemens SITRANS T3K PA, Инструкция по эксплуатации

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Instruction Manual 7NG3213
90
SITRANS T3K PA
C79000-B7174-C55-04
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)
Channel 1 Channel 2
Parameter code 0 1 2 3 0 1 2 4
Open circuit
+ + – – + + – –
Short-circuit + – + – + – + –
+ Check enabled
– Check disabled
semibold normal state
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.