Siemens 181 Workshop Manual page 25

Parameters/address space
4.3 Explanation of Parameters
Note
Shared Device and "Reference channel of group 0, 1, 2, 3"
If the transmitter and receiver for the reference junction temperature of a group are assigned
to different IO controllers, then both IO controllers must be performing data exchange with
the IO device to ensure error-free operation of the temperature compensation.
Reference junction using the PROFIBUS GSD file
A BaseUnit with an internal temperature sensor (BU..T), the reference channel of
group 0, 1, 2, 3, or channel 0 of the I/O module can be used as reference junction for the
TC measurement, if this has the parameter setting "Thermal resistor Pt100 climatic range
Degrees Celsius".
The set temperature unit (e.g. Degrees Celsius) is valid for the entire module with
temperature compensation "Reference channel of the module" and "Reference channel of
group 0, 1, 2, 3".
Table 4- 6
Setting
No reference channel mode
Reference channel of group 0,
1, 2, 3
Setting
Channel x Reference junction
activated
Table 4- 7
Setting
Reference channel of the
module
Internal reference junction
24
RTD channel
Description
The temperature value at channel 0 can be used as a reference
value for the entire module.
The channel acts as a transmitter for the reference junction
temperature of a group. The distribution is performed via the
interface module.
Description
Disable: Channel x is configured with the setting
•
"No reference channel mode".
Enable: Channel x is configured with the setting selected above.
•
TC channel
Description
The corresponding TC channel uses channel 0 of the same module
as the reference junction temperature. This must be configured as
"Thermal resistor Pt 100 climatic range Degrees Celsius" and
"No reference channel mode"; otherwise, Diagnostics: Reference
junction is triggered.
The reference junction temperature is read by an internal
temperature sensor on the BaseUnit. Diagnostics: Reference
junction is triggered if there is an incorrect BaseUnit type.
Analog input module AI 4xRTD/TC 2-/3-/4-wire HF (6ES7134-6JD00-0CA1)
Manual, 02/2014, A5E03573289-AD