Advice on Mesa cards for 6 axis servo motors

Hi,

I have to buy hardware cards for a machine that is running with 6 drivers leadshine el5-d1000. (XYZ + rotary on spindle A axis + rotary on the table B- axis. ) Y axis has 2 motors like usual.

As I still have to order the cards , I would really like to know your opinions which cards would be best suitable and most easy to configure and most easily be connected to the drivers.

The connection to this driver is not step/dir and finished. There are like 44 pins connectors

I am a complete noob (as you might have guessed from previous posts) but learning every day.

Link to the wiring manual for el5 drivers page 18.:
www.americanmotiontech.com/upload/Manuals/el5-dm_v1.0.pdf

Hopefully someone here is working with the same drivers. I would like to get a lot better motion out of these drivers and motors than I currently do with mach3.

Thanks for your help .

Stephane

If you are running them with Mach3, then you are using them with step/dir signals. The reason the connector has 40+ pins is to accommodate all the possible optional configurations the drive supports. That doesn't mean they are all always used. (in fact the manual states 8 of the pins aren't even populated and are never used)

You need to decide on how you want to connect to these things, before hardware can be suggested.
Do you want to have encoder feedback?
Do you want to continue with step/dir commands, or use analog? (Analog control requires encoder feedback.)

There are far too many options available, you need to narrow the field by answering the above questions.

Hi Todd, thanks for your reply... It's just the help I need.

I want to move away of mach3 because it is not using any of the advantages the drives and servos have.

So I want to use these motors and drives to their full extent even if that makes the whole setup more difficult.

So yes I would like to get encoder feedback so I don't miss any steps .

Secondly any help on how the encoder feedback and directing it with analogue would help me build a better machine is welcome too.

I want to connect this drive the way it is supposed to be connected and not only with step dir commands . It makes the use of a closed loop system useless as the computer will never know if it made mistakes.(at least that is my understanding of encoder feedback)

Hope u can help me out a little further.

Thx
Stephane

Are you going to need to have a spindle encoder to? (That would meed you'd need 7 encoders)
Anyway if you only need 6 encoders you could go with some of Mesa's 50pin cards.
For Analog control of the servos, one of Mesa's 50pin header FPGAs.
How would you like to connect it to the computer, parallel port, PCI, PCIe, Ethernet?
Pair what ever FPGA card you like with...
A 7i48 has 6 encoder inputs, and 6 analog outputs.
store.mesanet.com/index.php?route=produc...rt=p.price&order=ASC
Plus a 7i37TA has 16in/8out isolated digital IO.
store.mesanet.com/index.php?route=produc...rt=p.price&order=ASC

If you want step/dir with encoder feedback.
Switch out the 7i48 for a 7i52s it has 6 encoder inputs and 12 differential outputs to use for step/dir.
store.mesanet.com/index.php?route=produc...rt=p.price&order=ASC

Thanks.

I'm not following the spindle part here. My spindle is controlled by the inverter and as far as I know that is controlled by a pwm signal. I don't see that there is any feedback from my spindle.

I am looking at the card you suggest. I was just wondering, these el5-d1000 drivers have 44 pins a piece. Like you suggested not all of the pins are used. But will 50 pins really handle 6 different drivers that's only 8 pins per driver. Is that all I will need to connect on these 44 pins connectors?

Secondly? Why would I need additional step/dir with encoder feedback. I thought that if using step/dir there is no feedback whatsoever. Would you be able to elaborate?

I am sorry if I come over as a complete idiot, but that's kind of how I feel recently ....

I just spend time on the phone with cncmonster.de who is selling the Mesa components in Europe.

They have advised me to purchase the 6i25 (PCI express connection) together with a 7i76 and combined with 7i85s to have a total of 6 drivers step/dir and 10 encoder feedback. Cause I have axis XYZAB with 2 drivers on the Y axis.

A 7i76 has one encoder input and 5 step/dir outs, a 7i85s only has 4 encoder inputs, and 4 step/dir outs. That is only a total of 5 encoders. There would be a total of 9 step/dir outputs.

If you use step/dir output encoder feed back is not necessary. But it can add some advantages such as, the ability to use Halscope when tuning the servos, recovery from E-stop without requiring homing the machine (Linuxcnc can still track the position even when the servo drive is disabled), monitoring following errors within linuxcnc, and closing the position loop within Linuxcnc.

I thought that you were wanting to take advantage of all of the possible features your servo drives offer, one of those features is an encoder pass through.

The 50 pin headers on the FPGA cards don't actually even have 50 io points/header (there are actually only 24), but through a great deal of electronic trickery the daughter cards that connect to them can greatly expand their capability. For example the 7i76 card connects with a DB25 plug with 25 pins, but only 17 are actually for data. But the card has many more input/output connectors than just 17 (or even 25). The 7i76 has 5 differential pair step/dir outputs, thats 20 wires just there, plus a +5v and GND for each of those sets (10 more wires), 8 wires for the spindle encoder, 3 wires for the analog spindle command, 4 wires for spindle enable and dir, 6 wires for an RS422 connection, and 48 more digital IO points. That is nearly 100 possible wire connections serviced by a single 25 pin plug. (and possibly a lot more if a Smart serial expansion card is added)

If you only use step/dir control to the drives, you are only going to use maybe 8 of the connectors on the drives 44 pin plug. 2 wires for step, 2 for dir, +5v, GND, an Enable, and a Fault

The shop told me the 7i76 has 5 encoder inputs and 5 step/dir.

Also said that better to use step/dir instead of analogue because it's a newer way of communication with less loss in signal.

I indeed want to get full use of the servos and drivers...

That is like saying digital music recordings are better than analog ones. There are many audiophiles who would beg to differ.