Applies To:
  • CitectSCADA 5.xx

The Generic APPLIC driver has a maximum request size by default of 2048 bits. However the Generic APPLIC driver can be used to communicate with a number of different device types using various protocols supported by the Applicom software. Some of these protocols have a maximum request size smaller than 2048 bits. For example, when used with the FIPWAY protocol, the maximum allowable request size is 960 bits. So the maximum request size must be made configurable. 

To permit a larger request size when required, version 2.03 of the APPLIC driver has added the Citect.ini parameter MaxBits as described below:

MaxBits Range: 0-2048 Default: 2048

The parameter is used as follows:

MaxBits =960

MaxBits should be a multiple of 8. If this value is modified from the default, then the protdir.dbf file in the Citect bin directory must be manually edited so that for the protocol, the BIT_BLOCK and MAX_LENGTH field is changed to match. For example if MaxBits is set to 960 bits for the APPLIC protocol, then the protdir.dbf should be modified as follows:

APPLIC APPLIC 960 960 0x0cb

If a specific APPLIC protocol is used (e.g. APPLIC1, APPLIC2...etc.), then the maximum request length should be correctly set for the chosen protocol, and no modifications will be necessary.