[daedalus]

Is there support in EMC for running the 5i20 card in hostmot-8 instead of hostmot-4?

I have seen an email mentioning hostmot-8 configs being committed to the cvs in dec 06, but cant find any documentation about them. (havent checked the cvs to see if they are there, just going on the email).

Has anyone tried using them, or is this just a work in progress?

Basically i already have all the hardware to do 4-axis, and i want to have a spare channel for initially just a spindle encoder, but eventually a spindle controller. Also it wouldnt hurt to have the option of 5-axis in the future (when my bank balance recovers a bit).

One issue i see so far is that i dont have a way of isolating the motor pwm and dir signals, or the encoders. Whilst i can get a board from mesa to isolate the io, there doesnt seem to be one for the motors, and the pinout is different. Does anyone with one of these boards have any ideas? is it really necessary?

[samco]

I have a mesa card although it is still in the anti-static bag.. Without looking I thought the hostmot-4 has 8 encoder inputs but only 4 pwm out. In all honesty you really should join the emc users email list. You will get much better/faster responce.

http://sourceforge.net/mail/?group_id=6744

sam

[daedalus]

Actually i have been on emc-users-digest for a couple of years, and searching through the posts has revealed that there are several different firmwares available in the cvs. Someone is working on a single firmware that can have between 0-12 servos attached, with excess pins dedicated to IO, but that hasnt made it to the cvs yet.

The best i can find for what i want to do is an updated hostmot-8 firmware, and a note that you have to write the firmware to the board manually, and tell the driver not to load firmware.

The one thing i havent been able to find is confirmation that these hostmot-8 firmware updates are supported by the software driver in EMC2, and that all channels are accessible.

I might just have to set it up and have a go, was just hoping someone else here had already done this and could save me some tinkering.

[unterhaus]

What are you driving that requires more than 4 outputs? I was thinking about that myself on my mill, 3 axes of x,y, z, rotary axis, and spindle.
Of course, since I have the Mesa 4 channel output board, there might be a problem with the extra output channels there, not just in software.

[daedalus]

the 5i20 is the anything-io pci card. It has 3 50 pin connectors which are defined by the cards firmware. Hostmot-4 is the default configuration for EMC, where one 50 pin connector provides 4 servo channels, and two 50 pin connectors provide IO.

Hostmot-8 has 2 connectors for servo channels, providing a total of 8 channels, and only 1 for IO.

There is also mention of someone developing a firmware for EMC which supports any number of channels from 0-12, and automatically assigns the left over pins to IO, however i dont think this is in the CVS yet.

One side note, looks like Peter Wallace from mesa electronics is developing an SPI interface IO expander that will work with the mesa cards, so this would be one way of getting extra io and keeping all the servo channels.

I was planning to have X,Y,Z,A, spindle and leave a spare channel for a B axis. The two extra channels could have been useful if i had wanted to look into adding a toolchanger at some point.

From going through the mailing lists this seems to be an active development area, unfortunately my project has suffered a setback. My servos have a wierd encoder setup where i can't get commutation signals, so i have had to replace all of my servo drives with new brushless AC ones (which don't need commutation signals).

The cost of this change has wiped out my budget, and i have to sell off some of my surplus gear to cover the costs. One thing i might have to do is sell my mesa board and just use step dir (something i couldnt do with my old drives as they were just pwm torque controllers).

I might keep the board and look at moving to closed loop EMC at a later date, but for now i have other problems to deal with.

[unterhaus]

John Kasunich is working on the firmware. Not clear which parts he's fixing right now.

That make sense that the 8 channel uses the third connector for servos, I don't think I need it for i/o. I only have one i/o breakout board now anyway.

[samco]

He is adding stepper support to the mesa card. The way I understand it is similar to what daedalus said.. Sounds like you could pick any combo of servo/steppers/encoders and the rest would be defined as i/o. You would want to ask john about that. He is the guru.

What he is working on is trying to make the card user friendly to define said combo.

sam