NI 9870 Serial Port Communication

[hkhiroya]

Hi,

I have the 9870 rs232 serial module on a cRIO 9073 chassis. I have looked at the serial loopback example, added to my project, changed the input node to point to the right serial port. This works fine when I use a loopback connected to the serial port cable. 

However, when I connect the port to the serial port at the back of my pc (using female to female serial cable) and run the 'Serial Loopback DMA Rd (Host).vi' I cannot see any data sent on hyperterminal monitoring the com port of my PC. Also if I type any characters on hyper terminal I cannot see them being received by the LabView program.

Why is this happening? i.e. the example working well with a loopback adapter and not when connected to another serial port?

All help will be appreciated.

regards

Harshil 

[Mark_SAI · Accepted solution]

Hi,

Do you have any details on the cable you are using? You may need a null modem cable.

Do all the settings in hyperterminal match the cRIO? I.E: Baud rate/parity/start and stop bits etc

Could you take a screenshot of the hyperterminal settings and also the windows serial port settings? Could you attach your cRIO VI?

Many Thanks,

[hkhiroya]

Hi,

I have checked, and all my settings match the ones on the cRIO.

The cable I am using is standard (female to female) cable. I have given the link for it below.

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=215-426&...

I will try and use a null modem cable.

Also, I have attached the screenshots as requested.

Thanks for the help.

 Harshil.

[hkhiroya]

Attached is the windows port setting.

[hkhiroya]

Hi,

Thanks for the help. Null modem cable did the job.

Regards

Harshil.

[Dipsy]

Hello Mark,

I have connected NI 9870 on cRIO 9073.

Chroma power supply is connected to port 2 of NI 9870.

I am trying to communicate with it using DMA FIFOs.

I am able to send/write command to it like switching power supply replay ON and OFF.

But when I try to read from command *IDN?\n  I get blank response.(only spaces) 

do you have any idea what could be missing?

Any help is appreciated.

Thanks.

[sharda]

Hey Harshil,

I am trying to use the similar program, i guess its not working for me. I just want to write a string to the serial port. I have the example setup, no errors, but output either on computer or scope.

Can you please post the exmaple and also you talked about the loopback adapter, what is that? I think i may be missing some thing here.

I will greatly appreciate that.

Thanks,

Ajay