View Full Version : Question about the 595

09-05-2010, 11:16 PM
When I set my output to use only a certain number of channels in Vixen the whole 64 channels still work. I have tried different settings but there is still singnal sent to the other channels. Any ideas?

09-05-2010, 11:38 PM
If you have all the 595 chips installed you will always pass data thru the chips. If you set Vixen for only 16 channels (an example), the first time data is sent then it goes into the first 16 channels. The next data send will move the data from the first 16 channels to the next 16 channels and the new data in the first 16 channels. And so on.....

The work around if you don't want to see the LEDs for the unused channels is to setup Vixen for 64 channels and leave the ones you aren't using as OFF.

09-06-2010, 01:04 PM
So does that mean no matter how many channels I select to run it will alway put out signal to the light on all 64. Example: I just ran a sequence that only required 17 channels of play. I set the output to 17 channel number 1 to 17. But when I ran it I was getting out put to lights from the higher channels also.

09-06-2010, 01:41 PM
You have all the 595 chips installed in your controller and when you send data to it, it sends the data down the data line connected to ALL the 595 chips. The solution for you is use ALL 64 channels in your sequence but leave OFF the channels you arent using. So if you only use 17 channels only put data in for those 17 channels and leave the other 47 channels blank in your sequence....

09-06-2010, 01:53 PM
The 595 is a serial shift register with a parallel output. As an example, let's say you have 17 channels that you're using but just wanted channel 3 to be on. The software would actually turn on channel 1 first, then step it to channel 2 and then channel 3. Channels 1 and 2 would only be on for a very short time so the lights would no actually turn on. To make sure that all the other channels were off, an off would need to be stepped all the other 16 channels in order. So each time that you wanted to change any channel, you have to step the on's and off's for all 17 channels.

If the controller has more than 17 channels, the on's and off's will be walked through them also but it will appear to be random values.

You need to set the controller channel count to at least the highest channel number that you intend to use.

09-06-2010, 04:24 PM
Actually, the 595 is a double-ranked shift register; as you clock data through it, it doesn't immediately show up on the output. When you pulse pin 12, that latches the data into the output registers.

09-13-2010, 06:50 PM
To simplify things: If you only want to use say 12 channels you still have to setup you control/sequence for 64 channels. What Vixen will send out to the 595 is what you tell it to do with those 12 channel and the rest of the channels will be sent out 'off' signals. then on the next cycle the same thing happens and the existing data is shifted out of the controller

12-03-2010, 08:36 AM
Ok here is my new query. When I do a light test with the 595 I check the channel I want to see light up and get nothing or I get a different light coming on from a different channe. But when I run the sequence they channel works. Example: I check channel 32, that channel is correct and the light comes on. I come back to the same channel later and the light does not come on during the test or a different light comes on. Now these are are within the same SSR's. Any ideas?