ERROR between two 'program movements'

MattiaDeiRossi

Hi all,

we are facing into an error between sending two consecutive program using the python api.

from the gui the first log is ES_BUS_ERROR but if the mcx-lastlog command shows the following errors:

2026-05-14 09:52:25.566 +0000 [INFO_SM] MotionSL0: Enter state: mcx::motion::motion_sl::MoveCommand 2026-05-14 09:52:25.566 +0000 [INFO_SM] MotionSL0: State: mcx::motion::motion_sl::NoCommand Event: startMove [done] 2026-05-14 09:52:25.566 +0000 [INFO_SM] MotionSL0: State: mcx::motion::motion_sl::MoveCommand Event: executeMove [repeat] 2026-05-14 09:52:25.566 +0000 [INFO] MotionGenerator: event = START_E, prevState = WAITING_MOVE_CMD_S, state_ = COMPUTATION_STARTED_S 2026-05-14 09:52:25.567 +0000 [INFO] MotionGenerator: event = START_E, prevState = COMPUTATION_STARTED_S, state_ = TRAJECTORY_READY_S 2026-05-14 09:52:25.568 +0000 [INFO] MotionGenerator: event = START_E, prevState = TRAJECTORY_READY_S, state_ = READY_TO_START_S 2026-05-14 09:52:25.576 +0000 [INFO_SM] MotionSL0: Enter state: mcx::motion::motion_sl::Moving 2026-05-14 09:52:25.576 +0000 [INFO_SM] MotionSL0: State: mcx::motion::motion_sl::MoveCommand Event: executeMove [done] 2026-05-14 09:52:25.576 +0000 [INFO] MotionGenerator: event = PLAY_E, prevState = READY_TO_START_S, state_ = RUNNING_S 2026-05-14 09:52:25.586 +0000 [INFO_SM] MotionSL0: State: mcx::motion::motion_sl::Moving Event: waitingToCompleteMove [repeat] 2026-05-14 09:52:27.686 +0000 [INFO_SM] MotionSL0: Enter state: mcx::motion::motion_sl::NoCommand 2026-05-14 09:52:27.686 +0000 [INFO_SM] MotionSL0: State: mcx::motion::motion_sl::Moving Event: waitingToCompleteMove [done] 2026-05-14 09:54:52.656 +0000 [ERROR] Drive1: Drive suddenly left Operation Enable state 2026-05-14 09:54:52.656 +0000 [INFO_SM] Drive1: Enter state: mcx::drive::Fault 2026-05-14 09:54:52.656 +0000 [ERROR] Drive2: Drive suddenly left Operation Enable state 2026-05-14 09:54:52.656 +0000 [INFO_SM] Drive2: Enter state: mcx::drive::Fault 2026-05-14 09:54:52.656 +0000 [ERROR] Drive3: Drive suddenly left Operation Enable state 2026-05-14 09:54:52.656 +0000 [INFO_SM] Drive3: Enter state: mcx::drive::Fault 2026-05-14 09:54:52.656 +0000 [ERROR] Drive4: Drive suddenly left Operation Enable state 2026-05-14 09:54:52.656 +0000 [INFO_SM] Drive4: Enter state: mcx::drive::Fault 2026-05-14 09:54:52.656 +0000 [ERROR] Drive5: Drive suddenly left Operation Enable state 2026-05-14 09:54:52.656 +0000 [INFO_SM] Drive5: Enter state: mcx::drive::Fault 2026-05-14 09:54:52.656 +0000 [ERROR] Drive6: Drive suddenly left Operation Enable state 2026-05-14 09:54:52.656 +0000 [INFO_SM] Drive6: Enter state: mcx::drive::Fault 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: Enter state: logic::EStopOpenCircState 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: Enter state: logic::EStopOffState 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EngagedState Event: emergencyStop [done] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: E-Stop id: 607 (0x25f) subsystem: 1 slave info: 0 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EStopOffState Event: emergencyStop [done] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: E-Stop id: 607 (0x25f) subsystem: 2 slave info: 0 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EStopOffState Event: emergencyStop [done] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: E-Stop id: 607 (0x25f) subsystem: 3 slave info: 0 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EStopOffState Event: emergencyStop [done] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: E-Stop id: 607 (0x25f) subsystem: 4 slave info: 0 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EStopOffState Event: emergencyStop [done] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: E-Stop id: 607 (0x25f) subsystem: 5 slave info: 0 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EStopOffState Event: emergencyStop [done] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: E-Stop id: 607 (0x25f) subsystem: 6 slave info: 0 2026-05-14 09:54:52.786 +0000 [INFO_SM] Robot State: State: logic::EStopOffState Event: delayEvent [repeat] 2026-05-14 09:54:52.786 +0000 [INFO_SM] Motion Mode: Enter state: logic::ToPauseModeTransition 2026-05-14 09:54:52.786 +0000 [INFO_SM] Motion Mode: State: logic::AutoRunMode Event: gotoPauseModeEvent [done]

could you help us to identify which is the error? Is difficult to understand if it's a hardware-related problem or a software bug in sending or not the program

alexey

Hello. Please find explanation of the log below.

Reading the log

Phase 1 — Move runs and completes cleanly

09:52:25.566 → startMove arrives, MotionSL0 transitions NoCommand → MoveCommand → Moving, and MotionGenerator walks through COMPUTATION_STARTED_S → TRAJECTORY_READY_S →
READY_TO_START_S → RUNNING_S.
09:52:27.686 → move finishes normally (waitingToCompleteMove [done], back to NoCommand). No errors at this point.

Phase 2 — ₂ min 25 s of silence, then a bus-wide drop
09:54:52.656 → all six drives leave Operation Enable in the same millisecond and enter mcx::drive::Fault. That simultaneity is the key piece of evidence.
09:54:52.786 (130 ms later) → robot logic enters EStopOpenCircState → EStopOffState, raises emergency stop with id 607 (0x25f) on subsystems 1–6, and motion mode goes to
ToPauseModeTransition.
The drives drop before any second startMove shows up in the log — there is no MoveCommand between 09:52:27 and the fault.
All six drives lose Operation Enable in the same tick. A software command or a per-axis fault would not do that — only a bus-level or safety-circuit event does.
The next state is EStopOpenCircState — i.e. the safety/STO open-circuit branch, which is a physical/electrical signal, not a software one. That matches the GUI's ES_BUS_ERROR.

So the drives spontaneously left OP Enable while idle, and the controller correctly reacted by going into E-Stop and pausing.

Probable hardware causes (in rough order of likelihood)
STO / safety relay opened — E-Stop button, safety door, light curtain, or a loose wire in the safety chain dropped the STO line. EStopOpenCircState is the strongest hint here.
EtherCAT bus interruption — loose RJ45, broken cable, EMI, or a slave that briefly dropped out. Master loses cyclic comms → all drives fall out of OP Enable simultaneously.
24 V control supply dip / brownout on the drive logic supply.
A drive group sharing one STO channel was tripped by something external (e.g. cabinet door switch, contactor chatter).

Best regards,
Alexey