Siemens SIMATIC CPU 410 System Manual page 86

I/O configuration variants
6.7 Connection of two-channel I/O to the PROFIBUS DP interface
Module
AI 8x16Bit
Use in voltage measurement
The "wire break" diagnostics function in HW Config must not be enabled when the modules are operated with transmit-
•
ters.
Use in indirect current measurement
When using indirect current measurement, ensure a reliable connection between the sensor resistances and the actual
•
inputs, because a reliable wire break detection cannot be guaranteed in the case of a wire break of individual cables of
this connection.
Use a 250 ohm resistor (measuring range 1 to 5 V) to map the current on a voltage.
•
Use in direct current measurement
Suitable Zener diode: BZX85C8v2
•
Circuit-specific additional error: If one module fails, the other may suddenly show an additional error of approx. 0.1%.
•
Load capability of 4-wire transmitters: R
•
(determined for worst case: 1 input + 1 Zener diode at an S7 overload value of 24 mA to R
Input voltage in the circuit when operating with a 2-wire transmitter: U
•
(determined for worst case: 1 input + 1 Zener diode at an S7 overload value of 24 mA to U
AI 8x16Bit
Use in voltage measurement
The "wire break" diagnostics function in HW Config must not be enabled either the modules are operated with transmit-
•
ters or when thermocouples are connected.
Use in indirect current measurement
Use a 250 ohm resistor (measuring range 1 to 5 V) to map the current on a voltage.
•
Use in direct current measurement
Suitable Zener diode: BZX85C8v2
•
Load capability of 4-wire transmitters: R
•
(determined for worst case: 1 input + 1 Zener diode at an S7 overload value of 24 mA to R
Input voltage in the circuit when operating with a 2-wire transmitter:
•
U < 15 V (determined for worst case: 1 input + 1 Zener diode at an S7 overload value of 24 mA to U
e-2w
U )
z max
AI 6xTC 16Bit iso
Notice: You may use this module only with redundant sensors.
You can use this module with Version 3.5 or higher of FB 450 "RED_IN" in the library "Redundant IO MGP" and Version
5.8 or higher of FB 450 "RED_IN" in the library "Redundant IO CGP" V50.
Observe the following when measuring temperatures by means of thermocouples and assigned redundancy:
The value specified in "Redundancy" under "Tolerance window" is always based on 2765 °C. For example, a check is
made for a tolerance of 27 degrees when "1" is entered and 138 degrees when "5" is entered.
A FW update is not possible in redundant operation
An online calibration is not possible in redundant operation.
Use in voltage measurement
The "wire break" diagnostics function in HW Config must not be enabled when the modules are operated with thermo-
•
couples.
Use in indirect current measurement
Due to the maximum voltage range +/- 1 V, the indirect current measurement can be carried out exclusively via a 50
•
ohm resistor. Mapping that conforms to the system is only possible for the area +/- 20 mA.
86
> 610 ohms
B
> 610 ohms
B
Article No.
6ES7 331-7NF00-0AB0
= (R
B
< 15 V
e-2w
= R
e-2w
6ES7 331-7NF10-0AB0
= (R
B
6ES7331-7PE10-0AB0
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
* I + U ) / I
E max z max max)
* I + U )
E max z max
* I + U ) / I
E max z max max)
= R * I +
e-2w E max