Festo CECX-X-C1 Series, Manual

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System manual CECX / Digital input/output module CECX-D-8E8A-NP-2
CECX-II 17-12
Information
Modules of the same type that are installed within the same line must have
different address switch positions. Different modules (e.g. CECX-C-2G2
and CECX-D-8E8A-NP-2) may have the same address switch positions.
The lids for the K-Bus plug and the address switch must remain locked at
the last module in the line (to protect it against dirt and damage through
electrostatic discharge on contact).
17.6 Operating behavior
17.6.1 Short-circuit
The behavior of the module in the event of a short circuit is determined by
the configuration.
17.6.1.1 Short circuit scan not activated (default configuration)
When a short circuit occurs, all active output of the affected group are
switched off, the system variables
system.DOx_stat
are set to TRUE
and an error message is generated.
If the control continues to signal a logical 1 (output switched off) there is a
cyclical test to see whether the blocked outputs are still short circuited. The
periodic attempts to switch on can be set via configuration entry "Error ac-
knowledgement cycle time".
After the short circuit has been rectified the
system.Dox_stat
flags are
reset, information about the rectification of the error is generated, and the
outputs become available again. The outputs that were not active when the
short circuit occurred continue to function without any restriction.
If after a short circuit another short circuit occurs on a further output, the
same procedure as for existing faulty outputs applies.
17.6.1.2 Short circuit scan activated
In order to clearly identify the output that is causing the short circuit, the
short circuit scan can be activated in the configuration. In this case the out-
puts that were active during the short circuit are switched on in succession
for approx. 10 ms and tested for a short circuit.
The output affected is switched off, the
system.DOx_stat
- flag is set on
TRUE and the output is blocked. An error message for the short-circuited
output is generated.
The behavior during re-activation is the same as the one described above
without a short-circuit scan.