Firmware bug

We strongly recommend to fix this bug according to the guidelines mentioned below:

Products concerned:

314-6CF02, 315-2AG12, 315-4NE12, 317-2AJ12, 317-4NE12 only in connection with firmware version 3.52 (supplied since beginning of August 2010).


In individual cases the status of inputs is not transferred from the periphery into the peripheral image of inputs after STOP/RUN and Power On. This leads to the result that the status of inputs in the PLC programme is not recognized and therefore cannot be processed by the PLC programme.


Bug in the PLC operating system software. 


  •  Downgrade to firmware version 3.51
  • Update to firmware version 3.53 (availlable from 13.12.2010)
  • In case of simple peripheral structure copying the peripheral bytes concerned (central/decentral) into the input process image is a practical solution. The copying must be done prior to the first instruction in OB1.


Firmware 300S

The firmware version installed on the CPU on delivery is shown on the right-hand side under the case cover of the CPU.