I’m using LabVIEW to run an ZADSR245ProXR board. Everything on the LabVIEW side works. However, In a pre-sales discussion, there was comment that it is possible for an A/D input to be monitored by the ProXR’s onboard processor so that an independent safety circuit could enable some, if not all, relay outputs.
There are a ton of supplied LabVIEW examples… but none seem to show this capability. In looking through the supplied VI’s, I haven’t found one that enables/disables this capability.
How do I wire the ProXR24 to enable/disable on an external signal? The safety circuit outputs +5V when all is well and 0V when not. The signal is digital (hardware) can be inverted if necessary.
From what I read of the documentation, it seems I had a misunderstanding of the ProXR’s capabilities.
My situation is that there is a computer (running LabVIEW) that runs a machine and controls that machine via a ProXR board.
It turns out that occasionally, due to events beyond my control, the computer stops running the control program. This happens suddenly and without warning. An approximation of this activity would be an oscillating power failure that confuses a UPS and crashes the computer… but leaves the ProXR up and running.
That produces a machine not in control and represents A Problem.
In the past with another relay controller, the LabVIEW program oscillated a general purpose I/O bit to continuously retrigger a one-shot. The one-shot output runs another relay whose contacts supply power to a common lead of that relay board.
So if computer control stops then the oscillation stops, the one-shot times out, and disable common power… which shuts down the machine.
From what I read from the documentation, this isn’t how the ProXR board works:
What I was looking for is a way for an A/D input to turn OFF all relays that have been commanded ON by a host computer. While the A/D input is above (or below) some threshold then the host computer commands the relays. When the A/D input is below (or above) that threshold then the ProXR would turn off all the relays.
You wrote:
You can also monitor the inputs from your LabView software and
manipulate the relays as appropriate.
Of course. However, if the control software suddenly shuts down (power failure, act of God, whatever) then there is no time to command relays to open.
Basically you will need to send a command to re-set the timer on interval. If the timer isn’t reset then it will trigger the specified relay. If this relay is connected to the power supply of the relay, this will reset the relay controller.