Digital I/O

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Need a discrete configurable rs-422 driver I/O board for pc

Anyone have an idea where I can get an RS-422 I/O board to plug in the pc? I need 8 discrete RS-422 outputs that I can configure with a pattern, then send out. I need to connect the board to my product that has 8 RS-422 receiver inputs...


All I see from NI are RS-422 serial boards...






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Message 1 of 8
I'm confused by your question. RS-422 is an electrical specification. The NI boards comply with the specification and you can send any pattern you want with these boards. What are the exact requirements for these receivers?
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Message 2 of 8

The boards I see for RS-422 have one differential transmit and 1 receive line. They are made for serial communication to RS-422 devices.  I need a board with 8 differential transmit lines with RS-422 drivers (basically RS-422 signal levels, differential output) that I can discretely control, more like discrete I/O boards.


Does that help?



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Message 3 of 8
I recommend a PCI-8431/8. It has 8 ports and includes the converter cable (SCSI-68 to eight DB-9 male connectors). It will give you the 8 differential transmit and receive lines and the discrete control you need.
National Instruments
Applications Engineer
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Message 4 of 8
We have the same problem looking for a RS-422 discrete I/O board. The manual for this board, serial.pdf, makes no mention of how to use this card to set it high/low or low/high on command and to read a high/low or low/high on command. I use LabWindows for our application. What software commands set this card's output  to a static output or reads the input high or low? We plan to use this card for serial I/O anyway and my understanding of this device is that there is a UART behind the RS-422 interface and the outputs will either be tristated or if biased be in a high/low state when idle. I sent an email to NI tech support about this isue a couple of days ago and so far have received no response. Thanks. 
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Message 5 of 8
This board would not work for my application,as I also needed to synchronous control of the different discrete signals. I had to make my own board. Hopefully the NI engineer can help you.
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Message 6 of 8
There is a Geotest GX5642 that looks like it would do the job but I don't know the cost of the board. We were wanting to stay with NI for convenience and software and maybe cost. It's possible that 2 SE TTL type DIO channels would work, but you don't get the impedance matching if you need that. Based on your statement I wish NI would not leave an apparently erroneous statement on the forum without correcting it, since someone might purchase the wrong card. Not trying to desrespect NI, because I've used their hardware and software for years and think they have great products.
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Message 7 of 8
BTW I have a problem typing not spelling and just found the check spelling button. Also, if I knew how kudos to you for replying to an old post to help someone else.
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