GcodeDriverReaderThread Read Error at initial Connect

[Bert Sackett]

Duet3 6XD board 

Firmware 3.6.1,

connected USB 115200, Parity=None, DataBits=8, StopBits=One, Flow=Off, DTR=Set

OpenPnP  Version 2.4

Windows 10

USB Drivers for Duet3 downloaded from https://github.com/Duet3D/RepRapFirmware/blob/dev/Driver/WindowsDriverFiles.zip

Drivers.GcodeDriver set to same serial communications as the Duet3 board.

When I attempt to connect, there is an immediate Read error. Then I see the G21 command go out and a successful reply. After a few seconds there is a timeout message on the G21 command.

2025-10-27 12:35:35.935 ReferenceMachine DEBUG: setEnabled(true)
2025-10-27 12:35:35.935 GcodeDriver DEBUG: [Duet3_6XD_361:COM7] Connect
2025-10-27 12:35:35.935 GcodeDriver$ReaderThread ERROR: [Duet3_6XD_361:COM7] Read error: java.io.IOException: Read error.
at org.openpnp.machine.reference.driver.SerialPortCommunications.read(SerialPortCommunications.java:150)
at org.openpnp.machine.reference.driver.ReferenceDriverCommunications.readUntil(ReferenceDriverCommunications.java:108)
at org.openpnp.machine.reference.driver.ReferenceDriverCommunications.readLine(ReferenceDriverCommunications.java:86)
at org.openpnp.machine.reference.driver.GcodeDriver$ReaderThread.run(GcodeDriver.java:1512)
2025-10-27 12:35:35.935 GcodeDriver TRACE: Duet3_6XD_361 waiting for connection 3000ms
2025-10-27 12:35:38.948 GcodeDriver DEBUG: [Duet3_6XD_361:COM7] >> G21 ; Set millimeters mode, 5000
2025-10-27 12:35:38.948 GcodeDriver$ReaderThread TRACE: [Duet3_6XD_361:COM7] << {"seq":16,"resp":"\n"}
2025-10-27 12:35:43.953 MessageBoxes DEBUG: Error: java.lang.Exception: Duet3_6XD_361:COM7 timeout waiting for response to G21; Set millimeters mode
2025-10-27 12:38:10.996 AbstractMachine TRACE: Machine entering idle state.

Any ideas on what''s wrong?

Thanks,

Bert

[bert shivaan]

Does it connect with another terminal? SOmething outside openPNP?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/openpnp/465ebfa5-6ad5-4f4e-9b6d-75c990f31709n%40googlegroups.com.

[tonyl...@gmail.com]

I am not a Duet user (or expert), but I can see that your Duet is responding to the G21 command but just not with the "ok" that OpenPnP is probably expecting. The text highlighted is what the Duet is sending back as the response which appears to be some kind of JSON string.

2025-10-27 12:35:38.948 GcodeDriver$ReaderThread TRACE: [Duet3_6XD_361:COM7] << {"seq":16,"resp":"\n"}

That may be just fine (maybe some DUET experts here know), and you just need to get your COMMAND_CONFIRM_REGEX setup to recognize it. Probably best if you just use Issues & Solutions to guide you through getting everything setup. It should be able to detect what firmware you are using and do a lot of the setup work for you.