C-Series Module NI 9871, 4-Port, RS485/422 Serial Interface

[John Lee]

I have a question regarding the C-Series Module NI 9871, 4-Port, RS485/422 Serial Interface.

I need to find out how it recovers the data from the link. I need to compare it with 8b/10b encoding.

Does anyone know what UARTs are used or how the data is recovered.

Thanks

John Lee

[BB.]

Hi John,

Thanks for your post. I am not 100% sure what you are trying to ask . Would you like to know the differences in speed/data rate between this module and 8b/10b? Or more specific internal information about the RS-485/RS422 Transceiver? If you could give me more information I will try to help you as best I can.

Best Regards,

[John Lee]

Hi Benjamine

Thanks for getting back to me.

I wanted to know how the NI 9871 recieved the data on the RS485 link.

I believe it has a RS-485/RS422 Transceiver followed by a UART.

The UART will recover the data as per normal comms.

I need to recover data from a link which has 8b/10b encoding.

I think my answer is to use RS485 Transceivers and then push the serial data into an FPGA for data recovery and 8b/10b decoding.

Regards

John Lee

[BB.]

Hi John,

I have had a look into this and I cannot find any specific information on the Transciever or UART. However I have come across an example using the 9871 with processing on a cRIO FPGA.

To find this example open up Labview » go to Help » Find Examples » Search for 9871 and open up NI-987x Serial Loopback.lvproj.

Hopefully this should give you a good start. Once your serial data is passed onto the FPGA you can then decode the 8b/10b within the FPGA code.

Best Regards,