The value of tmnxMDADiffTimestampFreq specifies the differential
timestamp frequency of the differential clock on the MDA.
The value must be a multiple of 8 KHz.
This value can only be changed if the value of tmnxMDAClockMode is
'differential (2)' and there are no ports created on the MDA. If
there are ports created, a shutdown of the MDA is required in order
to change the value.
If the value of tmnxMDAClockMode is 'differential (2) then the default
is 103,680 KHz.
If the value of tmnxMDAClockMode is not 'differential (2)' then
this value is 0 KHz and cannot be changed.