Applies To:
  • CitectSCADA 5.xx

The Bosch PLC can use the RK512 / 3964R serial protocol. Can Citect communicate with these PLCs? 

Early versions of the Citect driver for the RK512/3964R protocol, called SIEMENS, made a status poll of a Peripheral Word of the device to check that the device is online before continuing with the normal Citect-device communications. The Bosch PLC does not support Peripheral Words. The SIEMENS driver was modified so that it polls for a more common register, namely the first two data words of DB0. As a result, the Bosch PLC is now supported using the SIEMENS driver.

Alternatively, the status poll can be disabled by using the 'Status' parameter. This is not recommended, as it may interfere with redundancy. Refer to the Citect help for more information on this parameter.