I am using an NI-9476 module in a cDAQ system (NI cDAQ-9133 Controller) to control some pneumatic valves. My software "environment" is Labview 2015 and Windows 7 embedded. My problem is that when the operating system is re-booted, the NI-9476 outputs are reset. I would prefer that they be un-altered during a re-boot so that the valves remain in their state at the time of reboot -- instead of all closing. Is there any way to disable the reset-on-reboot feature?
Could you give some extra background on when you see this behavior?
How are you controlling the pneumatic valves? Are you manually rebooting your device or does the 9133 reboot itself unexpectedly?
The pneumatic valves are actually opened (against a spring) when a solenoid is powered. The solenoid runs on 24 V power. I use the 9133 as a solid state switch to switch the power to the solenoid on when I want to open one of the pneumatic valves. I think this is a pretty standard way to open pneumatic valves. I had assumed that the states of the solid state switches in the 9133 would remain unchanged unless they were explicitly changed by a programmed command to the 9133. Unfortunately, apparently whenever the cDAQ computer is re-booted, it sends a reset to the module and all switches are turned off -- so the valves all close. This is really not appropriate for my application. We all know that Windows reboots (or has to be rebooted) from time to time. It is not a bullet proof operating system. There really should be a way to disable the reset-on-reboot to this module -- but apparently not. See the response from NI tech support on this question below:
unfortunately it seems that the module will have the output values reset because it has a Output Line Power Up State default, there are some modules that can change the value of the outputs
651x (6512, 6513, 6514, 6515)
652x (6527, 6528),
All M Series boards
All X Series boards.
Please let me know if you have any other concern,
Guess I picked the wrong module.
As far as I can tell, NONE of the modules suggested by the Applications Engineer at NI will actually plug in to my cDAQ computer which is an NI cDAQ-9133 Controller. This computer only accepts "C-series" modules. I'm also a little annoyed by the fact that there is no real documentation concerning the "Output Line Power Up State" which is apparently the culprit causing my module to reset all of its outputs when the computer is re-booted.
Actually I did find some documentation about what happens to digital outputs when the power is turned on at these links:
Note that my problem is not what should happen when power is restored to the module (I plan to use a UPS to be sure that there is time to deal with power loss). My problem is what happens when the operating system is re-booted. There is no reason to treat a re-boot like a power-restored condition.