Installation guide

Safety
890USE17100 September 2003 71
Safety Switching
Advantage of the
Power
Distribution
Method
One of the key features of Advantys STB island is the separate distribution of field
power to input and output modules. A PDM distributes field power to the input
modules via the island’s sensor bus and independently distributes field power to the
output modules over the island’s actuator bus.
This design provides an important safety feature during testing: With a simple relay
switch installed between the source power supply and the OUTPUT (actuator)
connection on the PDM, you can test your application program with live inputs while
the outputs are disabled. Activate the relay switch to prevent power from switching
the field actuators.
Here is an example of a safety relay switch setup:
Recommended
Safety Relays
Schneider recommends their Preventa line of safety relays. For a complete selection
contact your Schneider representative and ask for catalog DHMED 198043 XX.
24 VDC
P/S
24 VDC
P/S
NIM
24 V
PDM
24 V
IN
24 V
OUT
24 V
IN
24 V
OUT
24 V
IN
24 V
OUT
24 V
IN
Safety Relay/Switch
to sensor bus
to actuator bus
24 VDC