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View Full Version : G320 and Grex Encoder and Err/Res Hookup...



54Oval
04-07-2007, 12:31 AM
I'm setting up a controller using a Grex, 4 G320's and US Digital e5 500cpr encoders mounted on Nema34 motors. The Encoders are Differential and use US Digital adapters to get standard TTL signals.

The encoders are currently wired to the G320's, and the Err/Res is hooked up to the Enc+ terminal of its corresponding G320.

Everything works great with the first driver connected, but I figured since the Grex has encoder feedback why not hook them up allowing my software to check the actual motor position. I tried running the A and B Channels from the 320 up to the GRex, but this didn't work. If I power the encoders from the Grex's 5V and Ground and put a 470 ohm resistor across the G320's Enc+ and Enc- terminals can I run the A and B channels to both devices?

I would also like to monitor and reset the Err/Res using the GRex. Can I just connect each Err/Res connection to a GPO and also to a GPI, but I figured that I should ask before I fry something expensive.

Thanks for your help...

-Dan

Hi All... After talking to Mariss today I wanted to add a quick warning. Do not hook your Err/Res connection, or connect the Encoders/Ground Inputs of the Grex to the G320's Encoder and Enc- terminals. The Encoder section of the G320 must be optoisolated (sp?) from the Grex.


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Me Again. I found a solution to the Encoder circut. I've ordered a 24 Bit High Speed Opto-Isolation Board from cncbuildingblocks. www.cncbuildingblocks.com/files/24_Bit_High_Speed_Optov21.pdf.

The board is split in half with each half having its own power connections. By splicing the differential encoder signals and running them as the inputs to each half of the board, I will get two independent sets of Isolated TTL signals out for wiring to the GREX and G320's.