PXM PX245, Руководство пользователя

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BREAK
BREAK
MAB
M
B
F
M
B
F
M
B
F
M
B
F
M
B
F
START
CODE
DIMMER
1
DIMMER
2
DIMMER
3
DIMMER
511
DIMMER
512
full DMX packet
This means that even if we have a simple 6-channel lamp controller, the transmitter still have to
send 24 DMX channels. The interval between each frame of data is marked as MARK BETWEEN
FRAME (MBF) and can range from zero to 1 second. Thus, a complete DMX package looks as
below:
Obviously, sending time of one DMX data set depends on the number of channels. For a
minimum of 24 channels it is 1196 microseconds, and for a maximum of 512 channels it is 22 668
microseconds. Because of that, the maximum transmission change rate value is 836 Hz (for 24
channels), and in the second case only 44 Hz (for 512 channels). This is quite a serious limitation,
whose effects can be observed during fast movements of e.g. a large number of scanning
mirrors. Another quite important parameter is the minimum frequency of sending DMX packets.
According to the standard the rate is 1Hz. This means that the interval longer then 1 second is
considered as no DMX signal.
Unfortunately, creators of this protocol did not defined what should do in this case the receiver.
There are several possibilities:
- Maintain of the recently received DMX value,
- Immediate shutdown of device (BLACKOUT),
- Smooth device shutdown,
- During the lack of DMX it sends a previously predetermined value.
In the most applications a one of the first two solutions are used or the user is allowed to select the
one of the options with appropriate software.
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NOTE: Due to the lack of compliance with the DMX512 standard of multiple devices available on
the market below options allow to select appropriate parameters of the output DMX signal to a
specific device.
If you experience any problems, we recommend using bigger lengths of Break time, MAB, MBF,
and packet gap.
1. Break Time allows to change the length of the interval between successive DMX packets.
Break signal may take longer, but can not be less than 88 microseconds. Usually it lasts about
120-140 microseconds.
At the top of the screen next to
the option name are visible
important information that
simplify setting an appropriate
value.
To save the value before
leaving level up in menu You
need to select floppy disc
button and press
. „enter”