Devices With Ossd Outputs; Voltage-Free Contacts - Allen-Bradley Guardmaster GuardLink User Manual

Chapter 4 Power, Ground, and Wire
44

Devices with OSSD Outputs

Devices with OSSD outputs perform their own short circuit detection. The
DG can be configured to accept up to two devices with OSSD signals.
Connections of the OSSD outputs are shown in
Figure 31 - Wiring to Devices with OSSD Outputs
+24V DC
A1
A2
A1
A2
24V Com

Voltage-free Contacts

Devices with voltage-free contacts must use the pulse testing outputs to detect
short-circuit faults between the following:
• Channels
• Channels and power
• Channels and ground
Figure 32 shows the recommended wiring for dual-channel and single-channel,
voltage-free contacts. Voltage-free contacts can be connected to either Input 1,
Input 2, or both inputs.
Figure 32 - Wiring to Voltage-free Contacts
Device 1
S21 S22
S11 S12
Input 1
Pulse
Testing
Outputs
DG Safety Relay
Dual Channel
Rockwell Automation Publication 440R-UM015C-EN-P - April 2018
Figure
Device 1 Device 2
A1
A2
S12 S22 S32 S42
Input 1 Input 2
DG Safety Relay
Device 2
S42
S32 S21
S11
Input 2
Pulse
Testing
Outputs
31.
Device 1 Device 2
S22 S42
S12 S32
Input 1 Input 2
DG Safety Relay
Single Channel