More Inputs please ??

[Biggermens]

Hello everyone

what is the best solustion for more then 8 inputs for my router table ?
I have 3 gekodrives driving 3 stepper motors and i would like to add a mpg and encoders on my steppers ??

Thanks for all your help
Big

[ger21]

Another parallel port.

Why do you want to add encoders? There's no benefit to using encoders with steppers.

[Biggermens]

Hello

Adding a other parellel port will only give me 8 more is thare somting that will give me maybe say 20+

[vger]

You might try these guys....

anything i/o

Trying to do an encoder on a stepper can be troublesome, especially using the parallel ports as input. Part of the reason is that the parallel port must constantly monitor the encoder at a very high rate for any change on it's output.

If you really need closed loop control, then you should consider switching to servos with encoders and servo drivers like the Gecko G320 or G340, or a full blown motion control system such as the Delta Tau PMAC.

Delta Tau - PCI

Steve

[Biggermens]

Hello Steve

that is exacly what i was looking for I wonder if this board will work with mach3 ??
7I61 FPGA based High Speed USB Anything I/O card
Do you think that I/O card would be fast enough to run encoders ??

I would like to keep my steppers and my gekos just cuz i got them for almost nothing

Thanks
Big

[vger]

Big,

I don't think Mach has a plugin for the anything IO's. EMC does for some of them.

Mesa Electronics Anything I/O boards (plus all the Servo & Stepper Daughter Boards, etc) Mesa Electronics
The Anything I/O boards are all based on FPGAs, so can be loaded with different firmwares at the start of EMC.

Firmware defines the number of encoder, PWM, stepgens and General Purpose IO.
5i20, PCI, 200K gates, 72 I/O pins
5i22, PCI, 1.0M or 1.5M gates, 96 I/O pins
5i23, PCI, 400K gates, 72 I/O pins
4i65, PC-104/Plus?, 200K gates, 72 I/O pins
4i68, PC-104/Plus?, 200K or 400K gates, 72 I/O pins
3x20, PCI-Express, 1.0M or 1.5M or 2.0M gates, 144 I/O pins

Just load the mesa fpga with the appropriate firmware to handle your encoders and steppers......

Do you already have a machine built that you are having problems with tracking on? Just wondering why you are needing encoders? I've been running a stepper machine for a couple of years now and the only time I have an issue with it skipping steps or hanging is if I run the motors up into their midband resonance range. And encoders would not help there except maybe to stop the machine because it lost track. If a stepper is missing steps because it's running too fast, you can't make it catch up by trying to make it run faster. I've seen comercial stepper driven machines ($40,000 range) without encoders that run just fine as production machines 8 hours a day for years.

Steve

[Biggermens]

I just wanted encoder as insurance i think i will just run 2 or 3 peralle port

[ger21]

Mach3 only supports 2 parallel ports.
A guy on the Mach3 forum has a Mesa card plugin, but it hasn't been released yet.
You might want to look at a Pokeys.
But I think you'll need to use the parallel port if you want real time encoder inputs.