Instrument Control (GPIB, Serial, VISA, IVI)

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send txt config file to 256 devices via rs232

Dear All,
I have 256 devices here and each of them i have to send a simple txt config file via hyper terminal and com port before doing further functional tests. (baudrate 9600 , txt file is about 30 very short lines only)
coz the test can take care all 256 device at one go.
however before the test, it's like hell to plug/unplug and send txt config via hyper terminal.
i think of a few ways to make my life easlier, appreciate if advices are given.
  1. I found a miltiple com ports product from moxa which expands up to 128 ports. Probably I can do a simple vi by LV8.0 and  send the txt config file to 128 devices twice to achieve this. But not sure the moxa product is fully supported with visa, and this moxa products i don't think they are cheap.
  2. I have quite a few NI-DIO-96 cards on hands. Wonder I can use them to simulate as a com port and write a vi to send the txt config file. Say I can put 5 cards in one PC, then i will have 96x5=480 digital channels. 480/9pins= ~53 com ports to devices? and run the vi 5 times to get 256 devices done?
  3. If 1 and 2 are not possible solutions, found from NI page, they do 16 ports RSR232 products   since the price is reasonable. then i build a switch board, control by NI-DIO card and LV to swtich 16 times for 256 devices

What do you all think?



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Message 1 of 4

The DIO-96 has static digital I/O. It is software timed and you would find it very difficult, if not impossible to emulate the required timing in software.

I suspect that the MOXA would work fine with LabVIEW. As long as it's drivers installs ports that windows will see as addtional com ports, there's usually not a problem. Sometimes, you can request an evaluation unit or one contingent on it working with LabVIEW.

To make the MOXA completely automatic, wouldn't you have to build a switch board anyway? There would certainly be less switches required than option 3 though. Option 3 would be done with a custom board connected to each of the 16 ports and each board would mux to 16 different devices?

I think you'll have to find out the price of the MOXA and compare it to building multiple switch boards. I don't have the information near me right now, but one of the people that used to work with me designed an 8x10 switch matrix with USB control. I think the cost per board was well under $200.

Message 2 of 4
Thanks Dennis,
Time is critical, if DIO as rs232 is difficult, cant be bothered to try.
I am still waiting the quote from MOXA, let see how much the board is...
Btw, I am pretty interested how your colleague's 8x10 matrix usb board...
Is it connected to PC via USB and output 80 rs232? and windows sees 80 ports as standard comports?
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Message 3 of 4
The 8x10 matrix board connects to the pc and shows in MAX under USB Devices. Each board is one device. We used the Instrument Driver Wizard to create an inf file for it. A series of VISA Writes command it close a row/column address.
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