<![CDATA[Strange Modbus Behavior]]>Hi All,

I am using an NTC sensor module that I have used before with no issues. I now get this issue where the module (slave 1) seems to not work. I get a reading on val0 but it will not update, val1-9 are not plugged in but show the correct error value for open circuit, -500. If I place the cursor over the val0 it shows the reading but in red, sometimes orange. I have looked in the system log and it says that slave 1 is not responding. But I do seem to get an initial reading and the block itself never shows red when the cursor is over it. The valve of val0, 200 is 20 degC which would be correct. Any ideas what could be wrong here?

270b7cb7-48de-4b7e-b7bc-78491e9b2e3c-image.png

Cheers

Mike

]]>https://forum.rexygen.com/topic/208/strange-modbus-behaviorRSS for NodeSat, 18 Apr 2026 15:59:45 GMTMon, 01 Feb 2021 00:02:14 GMT60<![CDATA[Reply to Strange Modbus Behavior on Mon, 01 Mar 2021 09:08:09 GMT]]>@mikeyh Hi Mike,

thanks for update. Could you please try to test one Raspberry Pi with certain SD card (i.e. OS) and check with working Monarco HAT and then switch the one failing so we can say it is Monarco HAT failure afterwards?

Thanks for cooperation.

Kind Regards,
Tomas

]]>https://forum.rexygen.com/post/850https://forum.rexygen.com/post/850Mon, 01 Mar 2021 09:08:09 GMT<![CDATA[Reply to Strange Modbus Behavior on Wed, 24 Feb 2021 19:00:31 GMT]]>Update,

I have now tried a 3rd Monarco and it works as perfectly as the second. How can I test the 1st Monarco to see if it has a fault?

Cheers

Mike

]]>https://forum.rexygen.com/post/847https://forum.rexygen.com/post/847Wed, 24 Feb 2021 19:00:31 GMT<![CDATA[Reply to Strange Modbus Behavior on Tue, 09 Feb 2021 03:53:11 GMT]]>Hi Tomas

I solved this by swapping the Monarco for one that I know works. Could that Monarco have an issue, it's new? It's the same one mentioned with the strange voltage leak I posted about, https://forum.rexygen.com/topic/209/leakage-from-usb

Cheers

Mike

]]>https://forum.rexygen.com/post/812https://forum.rexygen.com/post/812Tue, 09 Feb 2021 03:53:11 GMT<![CDATA[Reply to Strange Modbus Behavior on Tue, 09 Feb 2021 01:56:19 GMT]]>@cechurat Hi Tomas,

here is the log from the Modbus

Modbus Log.csv

I get an initial reading then the comms seems to fail.

Cheers

Mike

]]>https://forum.rexygen.com/post/811https://forum.rexygen.com/post/811Tue, 09 Feb 2021 01:56:19 GMT<![CDATA[Reply to Strange Modbus Behavior on Wed, 03 Feb 2021 08:20:49 GMT]]>Hi Mike,

It seems that there is some communication problem - hard to say more without any diagnostics.

Please, can you turn on all I/O driver diagnostic messages (REXYGEN Studio -> Target -> Configure System Log -> I/O driver messages) and share a bit of the System Log with us? (REXYGEN Studio -> Target -> Show System log -> right click -> Export Items -> All items)

Kind Regards,
Tomas

]]>https://forum.rexygen.com/post/790https://forum.rexygen.com/post/790Wed, 03 Feb 2021 08:20:49 GMT