Siemens SIMATIC S7 - Page 759

Technical specifications
A.5 Thermocouple and RTD expansion modules (EMs)
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
759
Technical data
EM RTD 2 x 16 bit (EM AR02)
EM RTD 4 x 16 bit (EM AR04)
Cable length (max.), in meters
100 m to sensor max.
100 m to sensor max.
Wire re-
sistance
(max.)
except 10 Ω
RTD
20 Ω 20 Ω
10 Ω RTD
2.7 Ω
2.7 Ω
Table A- 126 Diagnostics
Technical data
EM RTD 2 x 16 bit (EM AR02)
EM RTD 4 x 16 bit (EM AR04)
Overflow/underflow
1,2
Yes
Yes
Wire break
3
Yes
Yes
24 V DC low voltage
1
Yes
Yes
1
The overflow, underflow and low voltage diagnostic alarm information will be reported in the analog data values even if
the alarms are disabled in the module configuration.
2
For resistance ranges underflow detection is never enabled.
3
When wire break alarm is disabled and an open wire condition exists in the sensor wiring, the module may report ran-
dom values.
The EM RTD analog expansion module measures the value of resistance connected to the
module inputs. The measurement type can be selected as either "Resistor" or "Thermal
resistor".
● "Resistor": The nominal range full scale value will be decimal 27648.
● "Thermal resistor": The value will be reported in degrees multiplied by ten (for example,
25.3 degrees will be reported as decimal 253).