After a couple days of near continuous printing, it seems like 3.2 has resolved my issue. Marking as solved.

After a couple days of near continuous printing, it seems like 3.2 has resolved my issue. Marking as solved.

@Phaedrux Awesome, trying that now. Will report back once I've completed some longer prints.

Thanks, I'll give 3.2 a try.

Standalone. Here is the text from M122. Are there any risks to trying the pre-release firmware beyond instability?

=== Diagnostics ===
RepRapFirmware for Duet 3 MB6HC version 3.1.1 running on Duet 3 MB6HC v1.01 or later (standalone mode)
Board ID: 08DJM-956BA-NA3TN-6J1D6-3S86P-TVBUT
Used output buffers: 1 of 40 (17 max)
=== RTOS ===
Static ram: 154604
Dynamic ram: 162536 of which 76 recycled
Exception stack ram used: 312
Never used ram: 75688
Tasks: NETWORK(ready,356) ETHERNET(blocked,436) HEAT(blocked,1188) CanReceiv(suspended,3820) CanSender(suspended,1488) CanClock(blocked,1424) TMC(blocked,204) MAIN(running,4528) IDLE(ready,76)
Owned mutexes: LwipCore(NETWORK)
=== Platform ===
Last reset 00:00:48 ago, cause: power up
Last software reset at 2021-01-04 22:41, reason: Memory protection fault, spinning module GCodes, available RAM 75392 bytes (slot 1)
Software reset code 0x4163 HFSR 0x00000000 CFSR 0x00000082 ICSR 0x04427804 BFAR 0x0100a8e4 SP 0x204128c4 Task NETW
Stack: 0040f6dd 00406f7c 21000000 004633e8 61000000 10000000 20415abc a5a5a5a5 a5a5a5a5 a5a5a5a5 a5a5a5a5 
Error status: 0
MCU temperature: min 28.7, current 37.6, max 37.7
Supply voltage: min 23.9, current 24.0, max 24.2, under voltage events: 0, over voltage events: 0, power good: yes
12V rail voltage: min 12.0, current 12.1, max 12.2, under voltage events: 0
Driver 0: standstill, reads 39130, writes 14 timeouts 0, SG min/max 0/0
Driver 1: standstill, reads 39131, writes 14 timeouts 0, SG min/max 0/0
Driver 2: standstill, reads 39131, writes 14 timeouts 0, SG min/max 0/0
Driver 3: standstill, reads 39132, writes 14 timeouts 0, SG min/max 0/0
Driver 4: standstill, reads 39135, writes 11 timeouts 0, SG min/max 0/0
Driver 5: standstill, reads 39136, writes 11 timeouts 0, SG min/max 0/0
Date/time: 2021-01-04 23:27:04
Slowest loop: 55.65ms; fastest: 0.21ms
=== Storage ===
Free file entries: 9
SD card 0 detected, interface speed: 25.0MBytes/sec
SD card longest read time 2.5ms, write time 0.0ms, max retries 0
=== Move ===
Hiccups: 0(0), FreeDm: 375, MinFreeDm: 375, MaxWait: 0ms
Bed compensation in use: none, comp offset 0.000
=== MainDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0  CDDA state: -1
=== AuxDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0  CDDA state: -1
=== Heat ===
Bed heaters = 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1, chamberHeaters = -1 -1 -1 -1
Heater 0 is on, I-accum = 0.0
Heater 1 is on, I-accum = 0.0
=== GCodes ===
Segments left: 0
Movement lock held by null
HTTP is idle in state(s) 0
Telnet is idle in state(s) 0
File is doing "M190 S65" in state(s) 0
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is idle in state(s) 0
Queue is idle in state(s) 0
LCD is idle in state(s) 0
SBC is idle in state(s) 0
Daemon is idle in state(s) 0
Aux2 is idle in state(s) 0
Autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 14.34ms; fastest: 0.03ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0), 0 sessions Telnet(0), 0 sessions
HTTP sessions: 2 of 8
- Ethernet -
State: active
Error counts: 0 0 0 0 0
Socket states: 5 2 2 2 2 0 0 0
=== CAN ===
Messages sent 191, longest wait 0ms for type 0
=== Linux interface ===
State: 0, failed transfers: 0
Last transfer: 48175ms ago
RX/TX seq numbers: 0/1
SPI underruns 0, overruns 0
Number of disconnects: 0
Buffer RX/TX: 0/0-0

Alright, so having updated to 3.1.1, I'm still getting resets. Had one long print succeed, then several resets only 10-15 minutes into prints.

@Veti This seems to have resolved my issue, running a couple longer prints to confirm. Will resolve once I've got a couple completed prints without a reset.

Repost from another part of the forums with better information and in the right place. Old post has been deleted.

I have been having problems with my Duet 3 on a coreXY machine resetting spontaneously mid print. The timing ranges from an hour into a print to 6 hours. I have not been able to cause the issue intentionally. Below is the result of a M122 after a crash (the printer has been power cycled, but the last software reset is what I've been seeing). I am running RepRap 3.01-RC-9. This problem seems similar to this question:
https://forum.duet3d.com/topic/19635/reset-during-print-part-2-duet-3-1-1-3-2beta3-duet3-sbc/14?_=1609649174634
where it was eventually resolved with a warranty. Config is attached config.g . Any assistance would be appreciated.

=== Diagnostics ===
RepRapFirmware for Duet 3 MB6HC version 3.01-RC9 running on Duet 3 MB6HC v1.01 or later
Board ID: 08DJM-956BA-NA3TN-6J1D6-3S86P-TVBUTUsed output buffers: 2 of 40 (11 max)
=== RTOS ===
Static ram: 154572
Dynamic ram: 161880 of which 44 recycled
Exception stack ram used: 288
Never used ram: 76432
Tasks: NETWORK(ready,132) ETHERNET(blocked,444) HEAT(blocked,1196) CanReceiv(suspended,3824) CanSender(suspended,1484) CanClock(blocked,1428) TMC(blocked,216) MAIN(running,4532) IDLE(ready,80)
Owned mutexes:
=== Platform ===
Last reset 00:00:58 ago, cause: power up
Last software reset at 2021-01-02 18:59, reason: Memory protection fault, spinning module GCodes, available RAM 76120 bytes (slot 1)
Software reset code 0x4163 HFSR 0x00000000 CFSR 0x00000082 ICSR 0x04427804 BFAR 0x81001838 SP 0x20411d0c Task 0x45485445
Stack: 0040fa2d 0040f8da 61000000 00000001 204118bc 20411d84 20411d60 a5a5a5a5 a5a5a5a5 a5a5a5a5 0040fa2d 
Error status: 0
Free file entries: 10
SD card 0 detected, interface speed: 25.0MBytes/sec
SD card longest block write time: 0.0ms, max retries 0
MCU temperature: min 30.2, current 39.5, max 39.6
Supply voltage: min 24.1, current 24.1, max 24.2, under voltage events: 0, over voltage events: 0, power good: yes
12V rail voltage: min 12.0, current 12.1, max 12.2, under voltage events: 0
Driver 0: standstill, reads 25276, writes 14 timeouts 0, SG min/max 0/0
Driver 1: standstill, reads 25276, writes 14 timeouts 0, SG min/max 0/0
Driver 2: standstill, reads 25277, writes 14 timeouts 0, SG min/max 0/0
Driver 3: standstill, reads 25278, writes 14 timeouts 0, SG min/max 0/0
Driver 4: standstill, reads 25281, writes 11 timeouts 0, SG min/max 0/0
Driver 5: standstill, reads 25282, writes 11 timeouts 0, SG min/max 0/0
Date/time: 2021-01-02 22:00:54
Slowest loop: 3.76ms; fastest: 0.14ms
=== Move ===
Hiccups: 0(0), FreeDm: 375, MinFreeDm: 375, MaxWait: 0ms
Bed compensation in use: none, comp offset 0.000
=== MainDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0  CDDA state: -1
=== AuxDDARing ===
Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0  CDDA state: -1
=== Heat ===
Bed heaters = 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1, chamberHeaters = -1 -1 -1 -1
=== GCodes ===
Segments left: 0
Movement lock held by null
HTTP is idle in state(s) 0
Telnet is idle in state(s) 0
File is idle in state(s) 0
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is idle in state(s) 0
Queue is idle in state(s) 0
LCD is idle in state(s) 0
SBC is idle in state(s) 0
Daemon is idle in state(s) 0
Autopause is idle in state(s) 0
Code queue is empty.
=== Network ===
Slowest loop: 4.90ms; fastest: 0.03ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0) Telnet(0)
HTTP sessions: 1 of 8
- Ethernet -
State: active
Error counts: 0 0 0 0 0
Socket states: 5 2 2 2 2 0 0 0
=== CAN ===
Messages sent 232, longest wait 0ms for type 0
=== Linux interface ===
State: 0, failed transfers: 0
Last transfer: 58326ms ago
RX/TX seq numbers: 0/1
SPI underruns 0, overruns 0
Number of disconnects: 0
Buffer RX/TX: 0/0-0