Check manual page of siemens_plc.flag
Siemens PLC: Binary flag values
The check monitors the state of binary flag values (single bits) reported by Siemens PLC (SPS) devices.
You need to use and configure the special agent agent_siemens_plc which is using the SNAP7
library to communicate with the Siemens PLC. When you are using OMD, everything is already
installed and configured. In manual setups, you will need to ensure that the snap7 library
and python module snap7 are installed.
To make temperature values available for the check, you need to configure the memory addresses
and data types to read from the device as temperature values.
By default the check reports OK for bits set to 1 and CRIT for bits set to 0, but you
can configure the check to handle them vice versa.
One check for each configured flag value is created automatically.