Applies To:
  • CitectSCADA 4.xx, 5.xx

 am getting a poor response from my TI5xx plc.  I also get the following errors in the syslog.dat file;

Fri Aug 13 10:39:07 1999 01:00:50.840 Error: General error
READ 0008 PORT2_BOARD2 IHS Y2977 16
Generic 000008 Driver 00004295 (0x000010c7)

Some of the driver errors, eg 0x10c7 are not documented anywhere, what does this mean ?

Also when I bring my primary I/O server back on-line, the plc never reattaches to the primary I/O server. What could be wrong?

Presently the TI CPU is set to a fixed scan time of 200msec.


1. The Fixed scan time should be set to variable, not fixed.  It may not service all communications requests.

2. Set the number of "task codes per scan" as high as possible.  This is very important to get a good response.

3. The error 0x10C7 is message queue full.  The message was rejected by the module because an input queue contained the maximum number of entries.  The module is receiving requests faster than can be processed by the plc.  The fixes suggested are;

Set task codes per scan = 8 (or as high as possible)
A fixed or large scan time will degrade the communications performance of the plc.

4. To counteract the 0x10C7error you may also need to tune the driver and set the parameters as follows;

Set [page] ScanTime = 10000 to reduce the number of requests from Citect
Set [TITCPIP]NumTimeOuts = 3 to allow three timeouts before reporting it to Citect
Set [TITCPIP]MaxOutStandingCampMsg = 1 to avoid out of Queue problem.
Set [TITCPIP] MaxPending = 10 to avoid out of NITP Queue problem.

See also the kbase Q2401 for more information.

5. The undocumented errors are returned by the CP2572 module.  Some errors returned from the plc module are not documented in the Siemens CP2572 manual, they were only documented in the original CIT manual.