Siemens PPU 26x.3 series Manual page 222

Connectable components
7.8 PP 72/48D PN and PP 72/48D 2/2A PN
Assigning parameters to the analog outputs
The analog outputs (AO) can be operated in the following operating modes:
Operating mode 3rd channel
No operating mode
Voltage output
Current output
Impermissible operating mode
Operating mode 4th channel
No operating mode
Voltage output
Current output
Impermissible operating mode
Checkback signal of the operating modes
The set operating modes are saved in the input image in status byte 0. This value must be
compared with Control Byte 0 in the output image. If these are different, an error has occurred,
e.g. in the case of overvoltage in the "Temperature measurement" operating mode, see
Diagnostics via input image (Page 224).
Example of programming
1. Determine control type:
2. Set the operating mode:
3. Query the error status bit in cyclic operation:
222
Bit 5 Bit 4
0 0
0 1
1 0
1 1
Bit 7 Bit 6
0 0
0 1
1 0
1 1
PPU and components
Manual, 10/2015, 6FC5397-2DP40-5BA3