ADLINK PCI-7260 - Manual (Page 40)

30 Operation Theorem
4.2 Emergency Shutdown
In safety-critical applications, users can enable the emergency
shutdown function on PCI 7260, to manually set the relay pattern
to preset state. To access this function, users must first configure
the emergency shutdown function by On Board Switch. Generally
the trigger source is on the front panel and connected to a push
button, which pulls the SHDNn pin to logic-High when activated.
The trigger source can be routed through the Onboard Local Bus.
The default relay pattern for emergency shutdown is All-Off on
PCI-7260 switch; users can change the pattern by change the Dip
Switch. Upon receiving the emergency shutdown trigger, the
Switch Module enters shutdown mode, and the relay pattern is
switched to the preset state.
The Emergency Shutdown function operation flow is as follows:
1. Emergency Shutdown button one shot trigger as shown
in Figure 4.2
Figure 4-2: 7260 Card with EMG_SHDN Trigger
2. When the trigger is active, the relay output will change
corresponding to EMG_SHDN Dip Switch(S3)
3. When entering Emergency Shutdown state, users can
not access the relay output pattern until they clear the
state through function _7260_EMG_SETUP().