Thermocouple Specific Parameters - Siemens SITRANS TH400 PROFIBUS PA Configuration Manual

3.8.3

Thermocouple specific parameters

Rel.
Parameter Index
PA
RJ_TEMP 33
RJ_TYPE 34
EXTERNAL_RJ_VALUE 35
RJ_COMP_WIRE 66
SITRANS TH400 PROFIBUS® PA
Configuration Manual, 02/2007, A5E01039143-01
Description
Reference junction temperature. The unit of RJ_TEMP is the
PRIMARY_VALUE_UNIT. If PRIMARY_VALUE_UNIT is no
temperature unit (e.g. mV) RJ_TEMP is stated in °C.
Select reference junction from internal to fixed value. Ignored for
sensors which are not thermocouple types.
Defined codes:
0 = No reference: Compensation is not used (e.g. for
TC type B).
1 = Internal: Reference junction temperature is
measured by the device itself, via
an internally mounted sensor.
2 = External: The fixed value EXTERNAL_RJ_
VALUE is used for compensation.
The reference junction must be kept
at a constant temperature (e.g. by a
reference junction thermostat).
3 = Sensor, 2-w.: Reference junction temperature is
measured by external 2-wire con-
nected Pt100 sensor.
4 = Sensor, 3-w: Reference junction temperature is
measured by external 3-wire con-
nected Pt100 sensor.
Fixed temperature value of an external reference junction. The
unit of EXTERNAL_RJ_VALUE is the PRIMARY_VALUE_UNIT.
If PRIMARY_VALUE_UNIT is no temperature unit (e.g. mV)
EXTERNAL_RJ_VALUE is stated in °C.
Value in OHM to compensate line resistance when External RJ
sensor, connected with 2 wires is used.
3.8 AI_TRANSDUCER Block (PA Slot 3) Parameter List
Type
Float
Unsigned
8
Float
Float
The Transducer Block
Size RO /
Store Min. Max. Default
byte R/W
D 4 RO
SRC 1 R/W
-40 135
SRC 4 R/W
(°C) (°C)
SRC 4 R/W 0 100
0
0
0
0
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