Dual channel n.c./n.o – Rockwell Automation 440C Guardmaster 440C-CR30 Configurable Safety Relay User Manual User Manual
Page 71
Rockwell Automation Publication 440C-UM001C-EN-P - November 2014
71
Safety Monitoring Functions
Chapter 9
Figure 80 - Example Schematic for Two OSSD
Dual Channel N.C./N.O.
The N.C./N.O. configuration applies the diversity concepts, where one contact
is open and the other contact is closed. The contact, while in an open state,
cannot be welded closed. The CR30 turns off its safety outputs when either
channel changes state. Both channels must change state for proper performance.
Figure 81 - Example Schematic for N.C./N.O. without Test Pulse
Figure 82 - Example Schematic for N.C./N.O. with One Test Pulse
Figure 83 - Example Schematic for N.C./N.O. with Two Test Pulses
If a short circuit occurs on terminal 12 to 24V, the CR30 turns off its safety
outputs within 35 ms. Remove the fault and cycle the contacts to clear the fault.
+24V DC
24V Com
Safeguarding
Device
A1
A2
05
CR30
02
01
00
03 04
A1
15
20 21
16
06
18
A2
07
19
08
10 11
12 13 14
09
17
+24V DC
24V Com
05
CR30
02
01
00
03 04
A1
15
20 21
16
06
18
A2
07
19
08
10 11
12 13 14
09
17
+24V DC
24V Com
A
05
CR30
02
01
00
03 04
A1
15
20 21
16
06
18
A2
07
19
08
10 11
12 13 14
09
17
A B
+24V DC
24V Com
05
CR30
02
01
00
03 04
A1
15
20 21
16
06
18
A2
07
19
08
10 11
12 13 14
09
17