Siemens SIMATIC S5 Manual page 338

Troubleshooting
Error Code
Recovery Procedures
F8A Reference point missing
F8B Max. following error exceeded
The maximum following error specified in the machine data was exceeded
and the current operation is aborted with a deceleration ramp. The
position control loop remains in force and the axis does not reach zero
speed until the following error has been reduced. The following-error
monitor is not activated unless the maximum following error is exceeded
despite axis movement or the actual value no longer changes and the
specified maximum following error is such that it is exceeded at an analog
voltage of less than 5 volts. Possible causes:
- Load torque too high
- Acceleration rate too high
- Loop gain too low
- Value specified as maximum following error too low
In these four cases, the axis can be moved in controlled jog mode. The
machine data must be adapted accordingly.
- The machine data specifications for maximum speed and
resolution are incorrect, i.e. were not matched to one another.
This can be checked by comparing the speed specified for controlled jog
mode with the displayed speed.
F8C Wrong PCB (module) number
Once the positioning module contains at least one correct machine data
record, it is no longer possible to change the module number. The number
stored can be viewed in COM 266's PRESETS form.
F8D Data block missing
F8E Wrong or no machine data
F8F Erroneous machine data
10-12
IP 266
Cross-
Reference
Section 5.3.5
Section 5.1.6
EWA 4NEB 812 6057-02