Meilhaus Electronic ME-5100 cPCI, Manual, Page: 21 / 43

3.7.3 Logic Level Matching
The signal level of all the digital inputs/outputs and of the control
lines can be switched together between 3.3
V and 5 V, depending
on the external circuitry. The changeover is made for all the ports
of the base board at once using software.
3.7.4 ”DATA_VALID” Pin
A high level at the DATA_VALID output indicates the validity of the
data at output port B in streaming mode operation.