NI Switch Executive - Model a relay system with no actual hardware

[kellymidge10101]

Hi,

I have a requirement to model a series of DPST relays in NISE.  My issue is the relays are controlled (switched) by driving the digital pins of a DTI card as required.  The relays are on a bespoke PCB.  My question is: can I create an IVI wrapper (in LW/CVI) that will allow me to control the relays when I request a connection in NISE?  It would mean I can add it to my switching system and hardwire and exclude etc.  I have no issue with the actual DTI driver code, I'm just not sure I can wrap it in an instrument which wouldn't exist in NIMAX so I couldn't open sessions etc.

I hope the question makes sense!

Regards,

Steve

[Frank-L]

Kellymidge10101,

My question is: can I create an IVI wrapper (in LW/CVI) that will allow me to control the relays when I request a connection in NISE?

Check out Use NI-DAQmx Digital Output Lines to Control Relays in NI Switch Executive . This is an IVISwtch driver that contains SPST relays that are actually controlled by a DAQmx device (NOT a Switch). This dll was created within CVI using the How to Develop an IviSwtch-compliant Driver to Use with National Instruments Switch Executive process.

I would recommend started from scratch in CVI using the IVISwtch driver creation tool in the second link above. 

Regarding Non-Existant hardware:

You can add some special tag in your driver session driver setup string that specifies simulation. 

You can than likely create code in your "connect" logic that reads the driver setup string to find the "simulate" flag and not actually call the dll that sends signals to the DPST relays.

[kellymidge10101]

Thanks Frank, that's set me off on the right path!

Steve