System Behavior

If an expansion module is removed or defective during run time, the input data of this module will be set to “0” and the module state will be set to the corresponding value (see MODBUS Communication Interface Module). A diagnosis message will be created in that case (see hardware description of CI521 / CI522 for diagnosis messages). \ \

In case a module is replaced, the new module will automatically be parameterized with the last parameters of the removed module (if single parameters were written to the previously removed module, this parameters will be ignored).

During pulling or plugging of a certain module, all other module will continue to operate with one limitation: The reaction time of modules connected to the right of the affected module will be bigger in that case (up to 50 ms).

If the bus failure detection is active for CI52x and failsafe is configured (see MODBUS Communication Interface Module) the following behavior applies if a module is removed and replugged during failsafe condition:

• Last value configured for output:
  • After a bus failure is detected, failsafe will be activated and the output will remain at its last value.
  • If the module is removed and plugged again, the output will remain off, and not be kept its last value, as the last value of the new module is “0” in that case.
• Substitute value configured for output:
  • After a bus failure is detected, failsafe will be activated and the output will be according to the configured substitute value.
  • If the module is removed and plugged again now, the output will be set according to the configured substitute value again.
• Substitute value for x seconds configured for output:
  • After a bus failure is detected, failsafe will be activated and the output will be according to the configured substitute value for the configured time.
  • If the module is removed and plugged again now, the output will be set according to the configured substitute value again, and the configured time starts again.