What does missing ACTCON mean?

It means the expected command activation confirmation was not visible in the evidence. Causes can include wrong command type, IOA, Common Address, select/execute policy, device support, timing, or session issues.

Should I check the event log or raw trace first?

Use both. The raw trace proves the protocol exchange, while the event log helps connect protocol confirmation to device feedback.

Command troubleshooting

Command sent, but ACTCON or final feedback is missing.

Command problems are painful because the operator can see a command action, but the protocol evidence may not show a clean activation confirmation, feedback, or termination. ARIEC60870 helps engineers read the command frame sequence instead of relying on a vague timeout.

Download ARIEC60870 Command flow basics

Normal evidence

A command should be traceable from request to confirmation and feedback.

Depending on the device and command mode, evidence can include select, execute, ACTCON, process feedback, ACTTERM, or a negative confirmation. Missing one of these does not always mean the transport is down.

RequestCommand Type ID, CA, IOA, qualifier, select/execute state, and direction.

ConfirmationACTCON proves whether the device accepted or rejected activation.

FeedbackEvent/value change proves whether the controlled object moved or changed state.

TerminationACTTERM may mark the end of the command flow when supported.

Likely causes

Do not stop at timeout. Check the command profile.

Wrong IOA or CAThe command reaches the device but targets the wrong object or station address.

Wrong command typeThe device may not support the selected command form or qualifier.

Select/execute mismatchThe device may require select-before-operate or reject execute-only behavior.

Session timingIEC-104 session or serial polling behavior may delay confirmation or feedback visibility.

Smart evidence

ARIEC60870 connects raw command frames to findings and report proof.

Use the Trace, Event Log, Smart Findings, and PDF Report together before escalating to vendor or commissioning teams.

CA mismatch IEC-104 session PDF evidence report