Chapter 3
Digital I/O Functionality
NI CVS-1450 Series User Manual
3-10
ni.com
Shutdown
Shutdown mode is a software-enabled feature, that when activated, allows
an external device to halt the NI CVS-1450 device processing operations.
Additionally, shutdown mode allows you to specify user-defined shutdown
states for all fault conditions.
When shutdown mode is enabled and the shutdown input signal,
ISO Input 11, turns off, the NI CVS-1450 device registers an external
shutdown condition. When this fault occurs, the
POWER OK
LED turns
red and all system operation halts. To resume operation, you must reset the
NI CVS-1450 device.
For all fault conditions, outputs operate according to user-defined
shutdown states. Each TTL output is configurable to drive high, drive
low, or 3-state, and each isolated output is on/off configurable.
Shutdown mode is unavailable when the
SAFE MODE
DIP switch is
turned on.
Refer to Table 3-4 for a summary of how user configuration affects the
shutdown condition.
Table 3-4.
Configuration Settings and Effects
Fault
Condition
Configuration Settings
Configuration Effects
SAFE
MODE
DIP
Shutdown
Enabled
Processing Halts
Outputs Change to
User-Defined States
External
Shutdown
On
N/A
N/A
No
Off
On
Yes
Yes
Off
Off
No
No
Watchdog
On
N/A
N/A
No
Off
On
Yes
Yes
Off
Off
Yes
No
Overheat
On
N/A
Yes
No
Off
On
Yes
Yes
Off
Off
Yes
No
