I have asked on duet forums and awaiting reply, cross posting here to see if anyone has any ideas...

Have a new Duet3 build wired up and working, done a test calibration cube which printed fine. However on longer prints the printer is failing after an hour or so (this is second occurence in a row now, hoped first was one off glitch).

02/06/2020, 19:42:57 	Warning: Lost connection to Duet (Timeout while waiting for transfer ready pin)

02/06/2020, 18:17:07 	M32 "0:/gcodes/[PLA ] CFFFP_Top - No Text.gcode"

File 0:/gcodes/[PLA ] CFFFP_Top - No Text.gcode selected for printing

Running 3.1.1, M122 info below. Search brings up a lot of info regarding 3.1.0 that was resolved with 3.1.1 so at a loss currently on what to do next.

M122

=== Diagnostics ===

RepRapFirmware for Duet 3 MB6HC version 3.1.1 running on Duet 3 MB6HC v0.6 or 1.0 (SBC mode)

Board ID: 08DJM-956L2-G43S4-6J9FA-3S86T-1B5LD

Used output buffers: 1 of 40 (10 max)

=== RTOS ===

Static ram: 154604

Dynamic ram: 162972 of which 56 recycled

Exception stack ram used: 224

Never used ram: 75360

Tasks: NETWORK(ready,1972) HEAT(blocked,1188) CanReceiv(suspended,3820) CanSender(suspended,1488) CanClock(blocked,1436) TMC(blocked,204) MAIN(running,4944) IDLE(ready,76)

Owned mutexes:

=== Platform ===

Last reset 00:47:22 ago, cause: watchdog

Last software reset at 2020-06-02 18:09, reason: User, spinning module LinuxInterface, available RAM 75056 bytes (slot 2)

Software reset code 0x0010 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0444a000 BFAR 0x00000000 SP 0xffffffff Task MAIN

Error status: 0

MCU temperature: min 35.5, current 35.7, max 40.4

Supply voltage: min 13.0, current 13.0, max 13.1, under voltage events: 0, over voltage events: 0, power good: yes

12V rail voltage: min 12.0, current 12.0, max 12.1, under voltage events: 0

Driver 0: standstill, reads 62000, writes 14 timeouts 0, SG min/max 0/0

Driver 1: standstill, reads 62000, writes 14 timeouts 0, SG min/max 0/0

Driver 2: standstill, reads 62001, writes 14 timeouts 0, SG min/max 0/0

Driver 3: standstill, reads 62001, writes 14 timeouts 0, SG min/max 0/0

Driver 4: standstill, reads 62001, writes 14 timeouts 0, SG min/max 0/0

Driver 5: standstill, reads 62005, writes 11 timeouts 0, SG min/max 0/0

Date/time: 2020-06-02 20:30:19

Slowest loop: 4.05ms; fastest: 0.14ms

=== Storage ===

Free file entries: 10

SD card 0 not detected, interface speed: 37.5MBytes/sec

SD card longest read time 0.0ms, 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

=== GCodes ===

Segments left: 0

Movement lock held by null

HTTP* is ready with "M122" 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 0, running macro

Aux2 is idle in state(s) 0

Autopause is idle in state(s) 0

Code queue is empty.

=== Network ===

Slowest loop: 0.68ms; fastest: 0.01ms

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: 0 of 8

- Ethernet -

State: disabled

Error counts: 0 0 0 0 0

Socket states: 0 0 0 0 0 0 0 0

=== CAN ===

Messages sent 11366, longest wait 0ms for type 0

=== Linux interface ===

State: 0, failed transfers: 0

Last transfer: 19ms ago

RX/TX seq numbers: 11820/26640

SPI underruns 0, overruns 0

Number of disconnects: 0

Buffer RX/TX: 0/0-0

=== Duet Control Server ===

Duet Control Server v3.1.1

Daemon:

Finishing macro daemon.g, started by system

> Next stack level

Code buffer space: 4096

Configured SPI speed: 8000000 Hz

Full transfers per second: 32.32