control NCD relay via USB

[HermanYang]

Hi,I need to use Labview to control National Control Device (NCD) ProXR relays via USB ComPort. NCD doesn't support the instrument driver now. Did anyone ever successfully control the 8 relays ? Can you share your VI source code? Thank you for your kind help.

[4Matted]

Hi,

Unfortunately National Instruments does not have any driveres on our website for your device. You should be able to communicate with your device by using VISA read and write commands. There are several examples already in LabVIEW to demonstrate VISA communication. I would encourage you to look through the examples provided by LabVIEW and try to establish communication with your device in that manner.

[HermanYang]

Hi NI helper,

   I already did try with VISA before I posted the question. The NCD device has no response to the input commands. I wonder if it requires CRC follows the command or special driver. Hope someone who has the successful example to show me. Thanks.

[Dennis_Knutson]

The manual should tell you if a crc is required. You haven't attached it so no one here can help. Attach it and an image of the front panel and block diagram so someone can compare what you have written to what the manual says. I would also recommend that you use a program such as putty or MAX before trying to write your own code.

[HermanYang]

I use PuTTY, set with right ComPort and use Serial communication. The screen is blank, can't take any input.

I try with MAX, set with ComPort, after open panel it accept Write with no error but still no reaction on NCD relay. I click Query with input command, it says "Time Out".

The Labview diagram is simple, I just use VISA to accept input after setting baud rate etc. It just doesn't react.

According to the vendor's manual, the shortest command (without API) is a string like "254 108 1" in which 254 is lead 108 is relay  and 1 is Bank.  If API is used the command will be like "170 3 254 108 1 24"

I wonder how can Labview accept this kind string.

[Dennis_Knutson]

What command did you use for the query? I hope it wasn't the IEEE-488.2 *IDN? command. That would be silly.

I have no idea what sort of string you are talking about since you still have not attached the manual. You mention api but don't provide an explanation of that means. I'm not sure how much help you can receive when you don't provide any information.