Reaction To Faults In The Control System - Festo CPV Series Manual

3. Diagnosis

3.4 Reaction to faults in the control system

PLC/ Reaction
protocol
- if PLC stops
Allen- Valves are
Bradley reset
DeviceNet
CP-DN8 9806NH
- to field bus
faults
Valves are reset when
timeout has expired
PLEASE NOTE
If all outputs are reset after a PLC stop or field bus
interruption, the following "pneumatic rules" must be
observed:
• unilaterally-actuated valves move to the basic
position
• double-solenoid valves remain in the current
position
• mid-position valves move to the mid-position
and (depending on valve type) are pressurized,
exhausted or blocked.
- to field bus
interruption
Valves are reset
immediately
3-9