SLF1: loss of local Modbus communication
In the manual ATV320 SLF1 identifies the interruption of the local Modbus serial communication. It is not the generic code for all networks and all options.
The case in 60 seconds
In the manual ATV320 SLF1 identifies the interruption of the local Modbus serial communication. It is not the generic code for all networks and all options.
Write down who controls the drive, protocol and if the problem also involves other devices.
The code or symptom directs research, but does not show the fault component alone.
Diagnostic map
Follow the rows in order. Each phase must produce evidence before moving to the next.
| Phase | Controls | Evidence to obtain | Next decision |
|---|---|---|---|
| 01Recognize and collect |
| Event context and complete initial data. | If a data is missing, do not reset to attempts: complete the initial picture first. |
| 02Check and separate hypotheses |
| External causes, configuration, circuit and separate process. | If the data does not match, return to the correct schema and revision before changing parameters. |
| 03Interpret and demonstrate |
| Cause supported by repeatable data and authorized evidence. | If the cause is not proven, stop changes and involve manufacturer, OEM or machine manager. |
Reading and observation
Recognize and collect
- Write down who controls the drive, protocol and if the problem also involves other devices.
- Record if the defect follows a switch off of the controller or a change of the network.
Event context and complete initial data.
If the result does not matchIf a data is missing, do not reset to attempts: complete the initial picture first.
Qualified technician
Check and separate hypotheses
- Compare serial address and settings with the design and configuration of the master.
- Check wiring and connections in safe conditions, distinguishing integrated door and optional card.
External causes, configuration, circuit and separate process.
If the result does not matchIf the data does not match, return to the correct schema and revision before changing parameters.
Specialist deepening
Interpret and demonstrate
- Correct the fault history with the master logs and with the management of the communications provided by the manual.
- Check command and reference channels, times and reaction to communication loss without neutralizing protections.
Cause supported by repeatable data and authorized evidence.
If the result does not matchIf the cause is not proven, stop changes and involve manufacturer, OEM or machine manager.
What to avoid
- Use repeated resets as a diagnostic test.
- Transfer codes, thresholds or parameters from one Drives family to another.
- Change a protection before connecting symptoms, measurement and phase of the cycle.
- Do not transform the loss of communication into uncontrolled march: a change of reaction to failure requires evaluation of the process.
When the problem is really solved
It documents the restoration of dialogue and the management of a controlled interruption provided by the testing procedure.
- The cause is supported by data and not only by the momentary absence of the alarm.
- The cycle that generated the problem has been repeated in authorized conditions.
- Final configuration, measurements and outcome are consistent with applicable machine, drive and documentation.
Applicable documents
Always check size, firmware, options and revision. These sources do not extend the case to other families.
- Primary source of the caseOpen the official source la
- Schneider Electric · Programming and DiagnosticManual · EN · NVE41295 · Official PDF