Technical data

5.6.5
ZYK (Cycle Time Exceeded
Error)
The cycle time includes the entire duration of cyclic program
execution. The cycle monitoring time can be exceeded owing to a
number of reasons: e.g. incorrect programming, a program loop in a
function block, failure of the clock pulse generator or by system
activities such as process image updating in conjunction with long
programs.
OB 26 When the cycle time exceeded error occurs, the system program
interrupts the user program and calls organization block
OB 26, if it is
loaded. This retriggers the cycle time monitoring. If the monitoring
time elapses again, before OB 26 has been completely processed, the
CPU goes into the STOP mode owing to a double call error
(DOPP-FE).
Cycle monitoring time The cycle monitoring time is variable (1 to 13000 ms) and can be
retriggered (see above). Regardless of the cycle time, 100 ms after the
cycle time has elapsed, BASP is activated if OB 26 has not yet been
completed.
You can select the cycle monitoring time by means of an entry in DX
0 or by calling the special function organization block OB 221.
In the cyclic program, the cycle time monitoring can be retriggered by
calling the special function OB 222.
STOP in the case of
unloaded OB 26
If you do not program OB 26, the CPU changes to the STOP mode. If
you do not want this to happen, you must change the default in DX 0.
No error identifiers If a cycle time exceeded error occurs, no error identifiers are
transferred to ACCU 1 or ACCU 2.
Errors in RUN and in RESTART
CPU 928B Programming Guide
5 - 56 C79000-B8576-C898-01