Shutdown Behaviour Of Outputs; (Hold/Stop) - Festo FB16 Electronic Manual

VIFB16 - 03/05
0506b
4. Commissioning
Shutdown behaviour of outputs (HOLD/STOP)
The outputs of the valve terminal react in normal
operation according to the PLC program. The
output words are transferred to the valve
terminal via the field bus at the end of each
program cycle.
This continuous update of the outputs can be
interrupted during operation by various events.
The different treatment of the outputs required in
this case can be set in the valve terminal.
There are switches in the field bus node of the
valve terminal for this purpose (see chapter 3.2,
Setting "HOLD/STOP").
•
STOP - the outputs of the valve terminal are
switched off at each event (error).
•
HOLD - in certain cases the outputs retain
their current status.
The following table shows the events with which
HOLD operation is possible.
Event
FIPIO bus interruption
Internal error in the
valve terminal
• module error
• short circuit/overload at
outputs
Controller at STOP
Fig. 4/26: Switch-off reaction of the outputs

(HOLD/STOP)

Switch-off reaction
Either switch off the
outputs (STOP)
or
retain the values last
received (HOLD)
4-55