NI PXI-8431 RS-485 max baud rate?

[LVLV]

I have a NI PXI-1045 chassis. I am using a NI-8431/4 RS-485 serial card that has up to 3 Mbit/s baud rate max.

Is there any NI-PXI RS-485 card available that has 4 Mbit/s or higher baud rate? If NO what are my options?

Can each channel (4 ch) in NI-8431/4 be programmed to handle different baud rate independently? 

Thanks for your help.

-LVLV

[pflores]

As noted in this KnowledgeBase, 3 Mbit/s is the max that we offer. Each channel is able to operate at its own baud rate.

Not sure what options you want to hear about. Your options to achieve a faster transfer rate could be to split a stream of data over two ports. For example, if you wanted to send the string "123456" at 6 Mbit/s, you can use two ports:

cpu A             |    data   |  cpu B   |  merge strings

port 1 (3Mbit/s)  |  1  3  5  | "135"    | "123456"

port 2 (3Mbit/s)  |  2  4  6  | "246"    |

Regards,

[LVLV]

Thanks.

Can you recommend any NI RS-485 PXI or non-PXI serial card that can handle 4 Mbits/s baud rate?

I have a requirement of at least 4 Mbits/s baud rate for RS-485 serial port in the project.

Thanks for your support,

-LVLV

[pflores]

Unfortunately, 3 Mbit/s is the max rate that we offer. A possible workaround is to split your data across two RS-485 ports as I tried to describe above. Also, remember that if you want 4 Mbit/s data throughput, you will need a higher baud rate to account for the overhead of the serial data. For serial interfaces, overhead can account for 25-50% of your data rate.

Good luck

[LVLV]

I found a RS-485 (PCI) commercial board that can handle up to 10 M baud rate.

I would like to keep my NI PXI-1045 chassis but I have to replace the NI-8350 rackmount controller with a commercial PC to handle the new RS-485 PCI board and the MXI-4 PXI-interface cards.

What software and hardware I need to make this work (running PXI chassis by a PC)?

Is it going to work or PXI chassis only works with NI-8350?

Please advise!!

Thanks,

-LVLV 

[pflores]

In order to control your PXI-1045 chassis from a desktop PC, you will need a MXI interface. It sounds like you may already have one, if not you can go with a PCIe option(MXI-Express) or PCI option(MXI-4). The main difference will be the form factor. Choose based on what slots are available on your host PC.

Once all connected, you will need a couple drivers in order to get things working.

- PXI Platform Services makes your MXI and chassis work with your computer, so it is a seemless extension of your PCI(e) bus.

- Depending on what PXI modules you have installed in your chassis, you will need to install the appropriate drivers (ex. NI-DAQmx for any Data Acquisition cards, NI-Switch for any Switch modules, etc.)

In short, you should be able to connect your PC to our PXI chassis by using a MXI interface.