Chapter 3 Programming
3 – 15
3.4 I/O-update
Input data is read at the beginning of a task and output data is written at the end of a task. I/O-update settings are
configured in “PLC settings” in Device tab. Be noted that only used I/Os in program are updated.
Update IO while in stop
If this option is activated (default), the values of the input and output channels get also updated when the PLC is
stopped.
Behaviour for outputs in Stop
Keep current values
: The current values will not be modified. If “Update IO while is stop” is deactivated,
output data is not updated at CPU stopping.
Set all outputs to default
: The default values resulting from the mapping will be assigned. If this setting is
used, “Reset all outputs in STOP” of [Device]-[Configurtion] parameter must be set as “No”, otherwise default
value of TRUE is not valid. Refer to the next page for further information.
Execute program
: You might determine the outputs behaviour by a program available within the project. Enter
the name of this program here and it will be executed when the PLC gets stopped. Via button [...] the input
Assistant can be used for this purpose.
Update all variables in all devices
If this option is activated, then for all devices of the current PLC configuration all I/O variables will get updated
in each cycle of the bus cycle task. This corresponds to option “Always update variables”, which can be set
separately for each device in the "I/O Mapping" dialog.
N o t e
If PLC settings are configured as follows (“Update IO while in stop” disabled and “Keep current values” in
“Behaviour for outputs in Stop”) and Reset warm or Reset cold is operated, the last status of output remains although
monitored output status is reset.
This is expected behaviour however, if this mismatching is to be avoided, change the setting of
either “Update IO while in stop” or “Behaviour for outputs in Stop”.
0 1 2 3
DC OUTPUT
EH-YTP16
4 5 6 7
8 9 10 11
12 13 14 15
Actual output remains
after Reset warm/cold
