231-E220

Check brake timing parameters

Access MOD function, select machine parameters, navigate to axis-specific parameters and verify MP7310 (brake activation delay) and MP7311 (brake release delay) settings.

Typical values are 50-200ms for activation delay and 100-300ms for release delay depending on brake type.

Monitor brake sequence in diagnostic mode

Use TNC diagnostic screen (CTRL+DIAG) to observe brake output signals and position controller status during axis enable/disable cycles.

Ensure machine is in safe condition before testing brake sequences.

Adjust brake timing if necessary

Increase MP7310 if brake activates too late, or increase MP7311 if brake releases too early, ensuring position controller is active before brake release.

Make small incremental changes (25-50ms) and test each adjustment.

Locate positionRangeVmin parameter

Access machine parameters via MOD function, navigate to safety parameters section and find MP positionRangeVmin for the affected axis.

Parameter location may vary by TNC version - check both general and axis-specific parameter groups.

Evaluate current setting against mechanical requirements

Compare current parameter value with expected mechanical backlash, thermal expansion, and brake settling distance for the specific axis.

Do not increase beyond mechanical safety limits - consult machine documentation.

Incrementally increase parameter value

Increase positionRangeVmin by 25-50% increments while monitoring alarm occurrence during normal operating cycles.

Document original values before changes and test thoroughly under various thermal conditions.

Perform brake holding test

With axis powered down and brake engaged, attempt manual axis movement to verify brake holding capacity meets specifications.

Ensure all safety procedures are followed and axis is mechanically secured during testing.

Check brake coil resistance and voltage

Measure brake coil resistance and verify proper voltage supply using TNC diagnostic functions or external multimeter.

Typical brake coils show 50-200 ohms resistance - check manufacturer specifications.

Inspect brake mechanical components

Examine brake disc, pads, and spring mechanism for wear, contamination, or mechanical damage that could reduce holding torque.

Look for brake dust accumulation, oil contamination, or uneven wear patterns on brake surfaces.

Check PLC program for axis commands

Review PLC ladder logic or structured text for any axis positioning commands that may execute during SOS conditions.

Look for unconditional axis moves or missing SOS status interlocks in PLC program.

Monitor PLC outputs during alarm condition

Use TNC PLC diagnostic screen to observe all outputs to the affected axis drive during SOS state activation.

Ensure proper safety procedures before inducing SOS conditions for testing.

Implement proper SOS interlocks

Add PLC logic to prevent axis movement commands when SOS status is active, using appropriate safety-rated input signals.

Use safety-rated PLC functions and ensure SOS status is properly communicated to all control systems.

Check following error at axis enable

Monitor position following error values in TNC position display during axis enable sequence to identify excessive error correction.

Following error should typically be less than 0.1mm at axis enable - larger values indicate positioning issues.

Verify encoder reference and scaling

Check encoder reference marks and scaling parameters MP4110-4130 to ensure position feedback accuracy.

Incorrect encoder scaling can cause large apparent following errors.

Adjust position controller enable sequence

Modify MP7300 (controller enable delay) to allow gradual following error correction without exceeding standstill monitoring limits.

Increase enable delay in 50ms increments while monitoring following error correction behavior.