Starting up LabVIEW (MAX) with connecting machine controller

[UPRR]

Hi,

I have developed one VI which controls signal Lamps through a mocrocontroler based PLC (VI is connected to PLC through NI 9188 and I/O modules and controls PLC to generate output for signal lamps).

Now the problem is if I give command to PLC through VI to generate some signals and then disconnect VI from the system and then connect VI again so while connecting VI again all previous bits status inside PLC goes down and off all the signals. so that means when VI connect to PLC it sets all the bits to zero. But I want all previously set bits status inside PLC as it is while connecting to VI again. please let me know if I am not clear.

Thanks

Prashant
 

[Cameron-T]

Is there anything else that would change the Lamps when you are not running the VI? In other words, if you use the VI to change the bit status and then disconnect will anything else change the bit status?

If not you could save the bit status in a shift register. As long as the shift register is not initialized then it should save the last value used.

Cameron T

[UPRR]

Hi,

Thanks for your response Let me explain, actually signals are controlled by the PLC I/O cards and PLC I/O cards are controlled by the NI 9188 chassis so we are controlling the PLC to generate signal outputs through LabVIEW.

The problem is when I connect my VI through NI 9188 all previously set signals get down and we need to set all signals again using VI.

Let me know if I am not clear somewhere

Thanks

Prashant

[Cameron-T]

When you set the bit status in your VI, before you close the VI go to Edit>>Make Current Values to Default. If you do this before you close it will start the VI using the same setting next time you pull it up.

Cameron T