Problem- G320 + HEDS-5540(encoder)?

[Vrogy]

I'm retrofitting an older mill which was driven by geared-down servomechanisms.

The encoders on the motors are HEDS-5540, either by Agilent or HP- a pdf I found on them is branded with Agilent, but they have an HP icon molded into them.
http://www.techshopdurham.com/wiki/uploads/HED-series optical encoders.pdf

The problem is, the G320 wants an encoder +, -, and phase A & B. The encoder puts out those, but also a channel I, for counting the index, or a full rotation.

Should I ignore this lead, can the G320 not make use of it?

[Bubba]

Yep, ignore it! There is no input on the Gecko to use it.

[keebler303]

Bubba is correct, you could however tie the index pulse to an input on your breakout board and use it for homing. A lot of commercial machines go until they hit a limit switch, then reverse until they get to the index pulse on the encoder. This gives you a repeatable zero within 1 encoder count. Could be much better than a switch setup, depending upon the type of switch you use.

Matt

[Bubba]

keebler,
Not trying to hi-jack, but I think?? it will take a tad more than just tying the index to the BOB!

[keebler303]

Obviously, you need to setup Mach or whatever controller you use to do that homing routine. I was not trying to be terribly explicit, just mentioning the general concept. The point I was trying to make was that although the G320 doesn't use the Index, it is useful, but only if you actually connect it to an input on your BOB.

As long as 5mA is enough to activate an input on your BOB (optocoupler might take more) then all you need is the index signal and the common from the encoder.

Matt

[Bubba]

keebler,
Thanks for the clarification as you and I are actually thinking along the same lines. I just didn't want somebody out there to get the idea they could hook the index to their BOB and have instant gratification!