Differential encoder e5 with the g320x

[dgalaxy]

Hi i just purchased a g320x driver for my nema 42 bridgeport today. i have been useing other drivers but i wanted to try the gecko because i have them on my plasma table and it seems there bullet proof . i have a question can i use my e5 us digital differential encoders with 10' cables on my new gecko or will i have major problems . i was going to just not use the extra channels as stated in other post on the encoders . just womdering if i will have major problems because of length of the cable
i was told i might have to run a seperate 5vdc to the encoder but thats ok.
John

[dmauch]

The E5 generally uses the 9140 read head which is the Heds 9100 series. You will need either a line driver or 1K pull up resistors added to the phase A and B on the read head. Without it the G320X will not come out of fault

[dmauch]

I have been testing the new G320X and am quite impressed. I initially set it up on my test bench as a drop in replacement for the G320. It ran very nicely right out of the package. I love the fact that it has an encoder fail detect and worked great. The short circuit protection works as advertised. I shorted the motor output connector for 5 seconds. No problem. The output went low and the servo amp suffered no damage.
A few days later I installed 3 of the G320X's on my knee mill that uses the knee as the Z axis. It doesn't have a counterbalnce so the Z axis motor which ia an Ametek 600 oz in peak servo motor is only about 120 oz in continuous with a 2.5 to 1 ratio reduction. I decided that I wanted to install the G320X without the covers on the knee mill because I see one problem with the G320X dip switch. You need to remove the cover to change the dip switch settings. To remove the cover you have to remove the servo amp from your heatsink. I recommend that Mariss on future versions punch a cutout in the top of the cover so that the dips switches can be changed without having to remove the cover.
I did notice a few minor issues that I reported to him about the rate multiplier and the motor gain switch selections which he indicated were changes that were fixed with key strokes. Otherwise, on the machine I had to make one change. I had to add a line driver because I was using the HEDS 9100 read heads in my encoders. For the encoder fail detect to work with this read head you need to either add 1K pull up resistors at the encoder or add a line driver. Since the line drivers are only $15 each I choose that method. With the X axis running at full speed I disconnected the encoder cable at the encoder. The machine came to a smooth stop.
One other problem that I had was that I had my PID setting a bit off so I wasn't getting the "in position light" which is a really nice feature that tells you the encoder is with +/- 2 counts of the ordered position. Tweaking the I value fixed that issue.
Other than the minor issues noted above, the G320X has performed really well and has given me at least 20% improved performance over the existing G320's. The other features that are really nice is the "I don'tcare if it's +5 or common signal ground" for the step and direction signals and works beautifully with the low voltage parallel ports. I used no breakout board in my tests other than a db25 to terminal blocks for making connections. I have machined quite a few parts and no funny issues have appeared. The G320X run very cool. I did notice an increase in dithering sound. Adjusting the PID made the sound comparable to the G320. So if you are planning to build or update your G320's I would say that the G320X is a excellent replacement.
The only thing I haven't tested was the stall feature. I am too chicken to run my machine into a stop or cause a stall.
So my test results have conviced me that the new G320X will be a great new addition to the Geckodrive line of products. Two thunbs up!

Dan Mauch
www.camtronics-cnc.com
low costc ases for Gecko drivers.
Stepper motors and servo motors