Sapphire Touch bad DMX timing

[StijnS]

Good morning everyone,

Lately I experienced some issues with our Sapphire Touch and Robe Pointe fixtures. Sometimes the lights flicker and sudden pan/tilt movements occur. I connected a DMX tester to the Sapphire Touch, and noticed the break time of the DMX signal is quite long.



In Setup>DMX Settings it is default set to 968, but I am unable to change this value.

How can I change the DMX timing to something more spec-compliant?


Kind regards,

Stijn

[StijnS]

Hello Avolites...? No one any ideas on how to set the DMX timing to something more normal?

Kind regards,

Stijn

[niclights]

Try enabling extra stop bit. This has solved these sort of issues for me in the past.

[StijnS]

Hi Nic,

Thanks for your reply. I am afraid setting the extra stop bit will not be of any help to this issue. But anyway, I did try it.
Let my clarify the issue with some pictures from an oscilloscope.

On the following picture you will see a normal DMX signal.

The data line is idle (floating) between the two DMX frames, and after the floating period, you can clearly see the break. (The low signal, 184 microseconds)

The following picture is taken at the output of the Sapphire Touch:

The entire time between two DMX packets, the line is kept low, thus indicating a really long break of more than a milisecond. I do know the E1-11 standard doesn't explicitly state a maximum break length, and they do allow for a zero length mark before break, but this kind of signal gives issues with some fixtures here. (To be specific: Robe Pointe's)

I tried to alter the break length in System>DMX Settings>Expert DMX, but the software doesn't accept new settings. The dialog window closes when I try to enter other values.

For now on, I will stick to using an Art-Net node together with the Sapphire Touch.


Best regards,

Stijn

[niclights]

Regarding the Expert DMX settings try doing it from the softkeys rather than clicking on the field. I think there are generally some issues with inputting directly to the fields in DMX settings but using the softkeys always works for me, including DMX timings.

This is a fairly specialist area. Don't know if you're in a position to phone but if you are still having problems I think the best person to speak to would be Adam.

[StijnS]

Hmm... Softkeys: good idea, didn't try that. I'll try it as soon as I get back in the warehouse.

Many thanks for thinking about my issue!

[adamabcd]

Hi,
A DMX compliant receiver should be able to accept the timings from the Sapphire Touch.
In fact it should be able to cope with a break length of up to approx 1000x as long as that sent from the Sapphire Touch.
Avolites found that some fixtures didn't like a short break length, or DMX sent at maximum update rate (44Hz).
So a decision was made to extend the default break setting, and so slow down the default update rate to about 42Hz.
Niclite's idea of adding the extra stop bit was a good idea. Maybe the change wasn't being accepted the in same way as the other settings?
I think that there's a conflict when changing the settings from UsbExpert when Titan is running.
So yes, changing them through the console software is the way to go.
Please post your results to let us know.