NI 9870 is no longer reading the data via serial communication

[StuJohn0455]

Hello all,

I have two NI9870 modules loaded onto my crio-9074 chasis. We have
followed the program given in the example
file(http://www.ni.com/example/31366/en/) line by line but we are not able
to read any data, it is always displayed as zero. Two things I want to
point out.

1) This program used to work earlier and now it doesnt( we havn't changed
the program ).

2) In the program after the first read block the value is always zero(as
marked by the arrow)

How can I figure out if the problem is with the hardware or some other error?

I would really appreciate any help, if anyone has faced a similar problem
earlier or has any clues on what I can try to rectify this issue.

[RavensFan]

Please just type your message into the editor and not into an "Insert Code" box.

You say something is marked by an arrow, but nothing is attached to your message.

Have you put any indicators or probes on error wires within the VI to see if they show anything?

[cbutcher]

Hi StuJohn,

---

@StuJohn0455 wrote:

I have two NI9870 modules loaded onto my crio-9074 chasis. We have
followed the program given in the example
file(http://www.ni.com/example/31366/en/) line by line but we are not able
to read any data, it is always displayed as zero. Two things I want to
point out.

1) This program used to work earlier and now it doesnt( we havn't changed
the program ).

2) In the program after the first read block the value is always zero(as
marked by the arrow)

How can I figure out if the problem is with the hardware or some other error?

---

1) If you changed nothing about the software, configuration, messages being sent, etc, then the software cannot be the culprit.

- If you changed any of these things, then it's possible that's the problem (or causes some other problem).

- Are you sure you didn't change anything?

2) Sounds like there's nothing to read.

How can I figure out ... hardware ... other?

If not software, then presumably hardware. My first suspicion would be the wiring, is it possible a wire was trodden on, bent, broken etc? Maybe there's no longer a (good) connection to your device and you're not getting anything back.

I would guess you checked nothing got unplugged/pulled out, and that everything is turned on 😉

If your system previously worked, and now doesn't, then something changed. The code in this example is pretty straightforward and so I doubt there's a weird corner case you're managing to hit, but even if there was, you should have been hitting it the whole time unless you changed something. The loop iteration values aren't connected to anything and there are no timing related steps, so it isn't the clock / running time...

[Yamaeda]

In some instruments i've had to unplug power and serial cable to fully reset the serial port and get communication working again. It seemed any residual voltage was enough to keep the buffer active or in some brownout phase.

/Y

[StuJohn0455]

I have attached the picture now, with the red arror, sorry didnt add it earlier. But as you suggested I added error probes and I am getting an error(I put a probe at the blue arror after calling the FPGA target, error code:-61017. Can you please explain possible reasons for this error as I had already mentioned the FPGA target was already complied and everything was working fine previously?

Also now should I just go ahead and re-compile my FPGA target?

[RavensFan]

Well since error Error -61017 says

"LabVIEW FPGA: You must recompile the VI for the selected target."

Then recompiling sounds like a pretty good idea!