Re: [Emc-users] MESA 7i43

[Viesturs L. <vie...@gm...>]

2011/7/3 Andrew <par...@gm...>:
> Hi,
>
> I consider purchasing 7i43 board to control 6 servo drives. First in
> step/dir, later in analog mode (with homemade PWM to analog
> convertors). As long as I have SPI encoders, I'm not sure it is that
> simple to connect them to EMC2 for analog servo mode, but I hope it's
> possible.
> Some questions:
> 1. There are several 7i43 models. I guess 7i43-U-4 is what I need?
> 2. Do I need any breakout boards, or servo drives and other stuff can
> be connected directly to 7i43?

I have servo drives working in step/dir mode in my waterjet machine.
My personal opinion - use analog signal from the beginning.

To move to analog control I have 7i43-U-4 and 7i48 daughter card (but I
have not yet installed them). 7i48 has 6 PWM-to-analog outputs and 6
encoder counters. But those inputs will not support SPI encoders.
If there is a chance to change encoders to "normal" quadrature ones,
this  might be exactly what You need - time savings would be
significant, which might provide also cost benefits, compared to DIY
pwm-to-analog converter.
You can connect directly to two 50-pin connectors of 7i43. I put
7i42TA in the welding robot to make the wiring easier. AFAIK 7i42 also
provides some protection from overvoltage in inputs. If You are
confident that You do not need that, You can easily do without it.

BTW, if You are not aware, there is a Mesa dealer in Czech -
www.duzi.cz I find them more convenient than purchasing from US,
delivery is much faster and total cost (price + shipping) is just a
little higher.

VIesturs