5.26.5.14. Setting the REFTA Error Counter to 16 000 
An interface is only selected as reference clock source if
- it is set to TMD and is Ready,
- it has the highest priority and an error counter < 42 000,
- it has the lowest error counter for the same priority level.
During integration tests, startup and switchovers for error diagnostics
the error counter can quickly rise to 65 535. Since it is only reduced
by 5%/h in synchronous systems, the established procedure was to remove
and re-install the peripheral board. This resets the error counter to
the starting value of 16 000. A REFTA command has been implemented to
set the error counter to 16 000 without affecting the peripheral board
or having to handle it.