BECKHOFF DK9222-0311-0029 - Manual (Page 3)

I/O
Light
Application Note DK9222-0311-0029
under certain circumstances. In such applications, several DMX universes must be connected in parallel.
Data transfer rate
DMX requires approx. 22 ms for the transmission of the data if the full frame length is transmitted, which is equivalent
to a refresh rate of 44 Hz. The human eye would perceive changes of light at this low frequency as ‘non-harmonic’ and
‘discontinuous.’ Fade up/down transitions only appear to be even at frequencies above 200 Hz. The data transfer rate needed
for harmonious fades/changes of light can only be achieved by reducing the amount of user data per universe and as a result,
the transmission duration of the frame is reduced.
No. of channels Refresh rate
512 ~44 Hz
64 ~300 Hz
16 ~1000 Hz
Ratio of data transfer rate to user data quantity
Note:
not all DMX Slave devices can work with a variable high refresh rate,
since the internal data processing is sometimes too slow.
Fig. 3 Increasing the DMX refresh rates
New Automation Technology BECKHOFF 3
For application notes see disclaimer on the last page