Siemens SINUMERIK 840D sl Manual page 132

Connectable components
9.3 PP 72/48D 2/2A PN
Table 9-50
Parameter
Input range (rated value)
Standard
Resolution
Accuracy
Internal resistance Ri
Note
If the PT100 operating mode is selected, the hardware is protected against overvoltage.
In the event of an error the following occurs:
1. An error bit is set which is then communicated to the PLC.
2. The module is shut down.
Measurement using a 4-wire connection system
Notes regarding the connection and operation of PT100 resistors:
This enables the module to supply X3 with a constant current via the CO1, CI1, CO2 and CI2
terminals. The constant current is fed to the resistor to be measured where it is then measured
as the voltage drop. It is imperative to wire the connected constant current cables directly to
the resistor.
Measurements with 4-wire connections compensate for line resistances and return a
considerably higher degree of precision in comparison with 2-wire connections.
x
ADU Analog Digital Unit
I
c
Figure 9-19
132
Technical data in the "PT100" operating mode
1, 2
Constant current
PT100 pin assignment
Value
- 200 ℃ to + 259 ℃
EN60751
16 bits (including sign)
+/- 2 ℃
>> 10 kOhm
NCU 7x0.3 PN, NCU 7x0.3B PN
Manual, 06/2014, 6FC5397-1EP40-5BA1