E1.20 RDM (Remote Device Management) Protocol Forums  

Go Back   E1.20 RDM (Remote Device Management) Protocol Forums > RDM User Forums > DMX512 Discussion

DMX512 Discussion Discussion and questions relating to DMX512-A and DMX512/1990.

Reply
 
Thread Tools Search this Thread Display Modes
Old November 21st, 2017   #1
Nelly
Junior Member
 
Join Date: Sep 2017
Location: Denmark
Posts: 7
Default Refresh rate from DMX controller

Hello there,

I have bought an Arduino board and a DMX shield to get the DMX functionalities to the Arduino. I have tried to connect the DMX shield to a LED driver that runs DMX but it seems like the LED driver doesn't get any DMX signal at all. Then I tried to connect the DMX shield to a Lightcorder (a device that can read the DMX signal). The lightcorder reads the DMX signal without any problem at all which tells me that the problem is between the shield and the LED driver.

I have also tried to measure a DMX signal (The LED driver can see this signal) send from another DMX controller to the LED driver and the only difference between the two signals that I know of is the refresh rate. The DMX shield is transmitting with a refresh rate of 19-20 Hz and the other equipment is transmitting with 40-41 Hz. Can this be the problem? Is it possible that the LED driver is made in a way that it can't receive DMX with a refresh rate that is 20 Hz?

Best regards
Christian
Nelly is offline   Reply With Quote
Old November 21st, 2017   #2
ericthegeek
Task Group Member
 
Join Date: Aug 2008
Posts: 358
Default

The refresh rate ("Hz") tells you basically nothing. What matters is the timing of the individual elements within the DMX packet. We can't really answer your question without having a lot more details about the setup. You'll likely need an Oscilloscope or DMX tester to get much further.
ericthegeek is offline   Reply With Quote
Old November 22nd, 2017   #3
Nelly
Junior Member
 
Join Date: Sep 2017
Location: Denmark
Posts: 7
Default

Hello again,

Thank you for the answer. I'm sorry for the lack of information but I'm quite new to DMX so I'm not 100 % sure about the information you want me to deliver. Can you please tell and I will find the information for you?

The Lightcorder is a kind of DMX tester as far as I know. It reads the signal and tells me the different DMX values on the different channels.

Best regards
Christian
Nelly is offline   Reply With Quote
Old November 22nd, 2017   #4
ericthegeek
Task Group Member
 
Join Date: Aug 2008
Posts: 358
Default

If you want to troubleshoot it, you'll need to look closely at the signal timing (min/max for break length, MAB length, byte spacing, etc.).

There are a lot of poorly implemented DMX devices out there. You may want to try a different LED driver.
ericthegeek is offline   Reply With Quote
Old November 29th, 2017   #5
Nelly
Junior Member
 
Join Date: Sep 2017
Location: Denmark
Posts: 7
Default

Okay and thank you for the answer!

I know for sure that the LED driver is of high quality. I have tried 3 different LED driver models from EldoLED and one LED driver from KKDC. The LED driver from KKDC make the LED flicker, when it receives the DMX signal. Does that tell you anything?

I will try to get an oscilloscop to check out the timing of the signal.

Best regards
Christian
Nelly is offline   Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
JESE DMX-TRI RDM USB Controller hamish RDM Marketplace Discussion 2 February 5th, 2016 12:07 PM
Sensor type and Sensor unit for DMX rate question berntd RDM General Implementation Discussion 3 October 1st, 2009 12:41 AM


All times are GMT -6. The time now is 09:51 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.