Hardware Manual for the PCD2.M5 Series│Document 26/856; Version EN 12│2014-07-24
Saia-Burgess Controls AG
Software watchdog
PCD2.M5_ Classic CPUs and expansion housings
3-51
3
As address 255 is in the normal I/O range, there are restrictions on the permissible
I/O modules in certain sockets:
CPU type
Restrictions
PCD2.M5_
1) No analogue, counter and motion control modules on the
socket with base address 240 (apart from PCD3.W3x5 and
PCD3.W6x5, which are not affected by the watchdog)
2) output 255 cannot be used for digital I/O modules
Watchdog - connection diagram
WD
WD
+24V
0V
WD
25 26 22 23
+
-
0
1
+
PCD2.M5_
Supply
Start
Bridging switch
for
CPU-Start
Process
Main switch
A-module
1)
Switching capacity of the watchdog contact: 1 A, 48 V
AC
/
DC
The status of the watchdog relay can be read via I 8107
“1” = Watchdog relay on.