Digital modules
8.5 SM 326; DO 8 x DC 24V/2A PM
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
133
Prevention/control of cross circuits between the P and M switches
To control cross circuits between P and M switches of a fail-safe digital output, we
recommend the following wiring variant:
/
0
/
0
'2[3
'2[0
60
'2['&9$30
Figure 8-39 Wiring scheme 2 relays at digital output of SM 326; DO 8 x DC 24V/2A PM - Controlling
cross circuits
Note
The module only detects a "wire break“ fault at the P or M switch of its output if the both
relays are wired separately to the P or M switches.
Assignable parameters for applications 1 and 2
Table 8- 16 Parameters of the SM 326; DO 8 x DC 24V/2A PM for applications 1 and 2
Parameters
Range of values
Type
Effective range
"Parameters" tab
F parameter:
F monitoring time
10 ms to 10000 ms
Static
Module
Module parameters:
Diagnostic interrupt
Activated/deactivated
Static
Module
For single channels or channel pairs:
Activated
Activated/deactivated
Static
Channel
Diagnostics: Wire break
Activated/deactivated
Static
Channel
8.5.4
Diagnostic messages of SM 326; DO 8 x DC 24V/2A PM
Diagnostics using the LED display
The F-SM indicates faults by means of its SF LED (group fault LED). The SF LED is
activated when the F-SM generates a diagnostic message.
The SF LED flashes as long as a cleared fault has not been acknowledged. It goes dark
when all faults have been eliminated and acknowledged.
The SF LED flashes until you acknowledge passivation following a module fault.
