Applies To:
  • CitectSCADA 6.10 Service Pack B


A mismatch in units.dbf between IOServer and Client may lead to a crash. Tracing introduced in 6.10 Service Pack B to detect this situation contained a fault, causing a crash instead of the intended behaviour (i.e. log to syslog.dat and raise a hardware alarm).



A hotfix exists for this issue (HF610B36541). Once applied, detection of a units.dbf mismatch will result in:

  • A log entry to syslog.dat of the form:
    <time> : UNIT HANDSHAKE: IOServer...
  • A hardware alarm will be triggered.

Alternately, a workaround may be effected by setting the following in Citect.ini:





This will disable the checking and the alarm; however this should generally NOT be used unless advised by Citect Support.