Missing device is retried forever [and blocks anything else]

[vanrein]

This is some output from v0.5.1 without the expected device connected:

DEBUG: Modbus TCP send = 00 00 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP send = 00 01 00 00 00 06 03 06 00 35 00 01 -> #12
DEBUG: Modbus TCP send = 00 02 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP recv = 00 00 00 00 00 03 03 83 0b -> #9
DEBUG: Modbus TCP send = 00 03 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP recv = 00 00 00 00 00 03 03 83 0b -> #9
DEBUG: Modbus TCP send = 00 04 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP send = 00 05 00 00 00 06 03 06 00 35 00 00 -> #12
DEBUG: Modbus TCP recv = 00 00 00 00 00 03 03 83 0b -> #9
DEBUG: Modbus TCP send = 00 06 00 00 00 06 03 03 00 32 00 04 -> #12

Note that the transaction identifier in responses is stuck at 00 00 and nothing else is tried.

Are you intentionally sending a provisional response "hold on, will keep trying... forever if need be"?

In any case, with other devices also on the bus, their communication also gets halted, so I suspect this is a bug, namely forgetting to remove the command that just failed.

[vanrein]

It's very instructive to remove the power from one device while scanning multiple.

[vanrein]

This is an example where I rip the power from one device and the other seems to end up queued forever while mbusd blocks on the powerless one and continues to try to send transaction 000e. Not ideal from a stability viewpoint :-)

Connected.  Me Happy.
Entering loop.  Should exit when mbusd disconnects.
DEBUG: Modbus TCP send = 00 00 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP send = 00 01 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 00 00 00 00 0b 03 03 08 00 00 00 15 00 12 00 01 -> #17
Device temperatures: 0 21 18 1
DEBUG: Modbus TCP recv = 00 01 00 00 00 07 10 04 04 00 d4 02 5a -> #13
Temperature 21.200000, moist 60.200000%
DEBUG: Modbus TCP send = 00 02 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 02 00 00 00 07 10 04 04 00 d4 02 5a -> #13
Temperature 21.200000, moist 60.200000%
DEBUG: Modbus TCP send = 00 03 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 03 00 00 00 07 10 04 04 00 d4 02 5a -> #13
Temperature 21.200000, moist 60.200000%
DEBUG: Modbus TCP send = 00 04 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 04 00 00 00 07 10 04 04 00 d4 02 5a -> #13
Temperature 21.200000, moist 60.200000%
DEBUG: Modbus TCP send = 00 05 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 05 00 00 00 07 10 04 04 00 d4 02 59 -> #13
Temperature 21.200000, moist 60.100000%
DEBUG: Modbus TCP send = 00 06 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 07 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP recv = 00 06 00 00 00 07 10 04 04 00 d4 02 5a -> #13
Temperature 21.200000, moist 60.200000%
DEBUG: Modbus TCP recv = 00 07 00 00 00 0b 03 03 08 00 00 00 15 00 12 00 01 -> #17
Device temperatures: 0 21 18 1
DEBUG: Modbus TCP send = 00 08 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 08 00 00 00 07 10 04 04 00 d3 02 59 -> #13
Temperature 21.100000, moist 60.100000%
DEBUG: Modbus TCP send = 00 09 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 09 00 00 00 07 10 04 04 00 d4 02 59 -> #13
Temperature 21.200000, moist 60.100000%
DEBUG: Modbus TCP send = 00 0a 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 0a 00 00 00 07 10 04 04 00 d4 02 59 -> #13
Temperature 21.200000, moist 60.100000%
DEBUG: Modbus TCP send = 00 0b 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 0b 00 00 00 07 10 04 04 00 d4 02 59 -> #13
Temperature 21.200000, moist 60.100000%
DEBUG: Modbus TCP send = 00 0c 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 0d 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP recv = 00 0c 00 00 00 07 10 04 04 00 d4 02 59 -> #13
Temperature 21.200000, moist 60.100000%
DEBUG: Modbus TCP recv = 00 0d 00 00 00 0b 03 03 08 00 00 00 15 00 12 00 01 -> #17
Device temperatures: 0 21 18 1
DEBUG: Modbus TCP send = 00 0e 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 0f 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 10 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP send = 00 11 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 12 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 13 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP send = 00 14 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 15 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP send = 00 16 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 17 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP send = 00 18 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP send = 00 19 00 00 00 06 03 03 00 32 00 04 -> #12
DEBUG: Modbus TCP send = 00 1a 00 00 00 06 10 04 00 01 00 02 -> #12
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP recv = 00 0e 00 00 00 03 10 84 0b -> #9
DEBUG: Modbus TCP send = 00 1b 00 00 00 06 10 04 00 01 00 02 -> #12

[vanrein]

In case you find it useful, this is the generating code for the output above.

[vanrein]

Interestingly, the return of power does not recover the interaction. The state of mbusd appears disturbed, and it cranks out only those failures for the once-failed transaction.

[3cky]

Could you also provide the mbusd debug log file, as described here?

[vanrein]

Sorry for the slow response; I was distracted by IETF 115.

I cannot reproduce it at this point, even though I tried two flavours of hardware (USB to RS-485) tokens.

I made many changes, but not to this core, so this leaves me a bit dissatisfied. Alas, I suppose we should close for now, and perhaps I can reopen the issue if I run into this again. I will then also supply the mbusd debugging output.