Encoders

wow... so my initial investment just jumped up by $200... I figured the boards I needed were the 5i25 and a daughter card totaling about 125... but Im guessing thats not necessarily going to work.

so I think I have what I need if I am going to do the 7i76e,

but if I want to tackle this via the second paraport, what are the steps I need to take to feed the encoder into the system and tune it? im not even really sure where to start.

Why do you need to control the spindle servo with analogue 0-10V?

You have a DYN4 drive right? You could use another input interface like Step/dir.

Then 7i96 ($119) plus 7i85 ($69).

Or 7i92M ($89) plus 7i85 ($69).

You just need 4 axis of step dir and encoder inputs right?

(I haven't used any of the boards listed. I use an odd combo of 7i43 and 7i76 for stepper based machines. The 7i43 is technically a 50pin card where as the 7i76 is a 25pin card, but with the right cable and firmware they work fine together. Mesa boards are quite versatile and configurable)

Just caught this thread so I might have missed some stuff, but it seems like maybe there's some confusion. (Been there!)

If using a Mesa eth card, it doesn't require a base thread, only a servo thread and from what I assume is by design, the thread rate and latency isn't quite as important as it is when using a PC's parallel port. This is because using a Parallel port you are relying on the PC's CPU to handle all counting and step generation which is fickle depending on the processor and only seems to get worse with newer processors. The mesa cards use an FPGA to do the actual step generation and encoder counting as firmware modules and are only dependant on the PC to read or write simple instructions. The ethernet cards are what I use, I have a 7i76e on one machine and a 7i96 on another. The breakout card you're currently using is a "dumb" hardware interface to it's reliant on standard hal components running on the CPU to do everything so results will not be nearly as good.

The 7i76e has alot more on board GPIO than the 7i96, but the I/O on the 7i96 is alot more versatile which as you will probably find with the DMM drive this will come in handy. The DYN4 drives use sinking I/O (NPN), which means you need to pull it down to DC common to activate a state change. The 7i96 uses SSRs which can have a seperate common for each output which is either positive or negative and you can use either positive or negative common for all of the inputs (not individually). The 7i76e is PNP only which means positive inputs and outputs exclusively. There is a 7i76ed which is an NPN version of the card, but once again, it's the whole card. Your current board is pull up or pull down so I'm not sure what works better for you depending on the other I/O you are using.

I have both a DYN4 with 1kw/5krpm spindle motor and a clearpath SDHC on another machine. I use step and direction with the DYN4 even though I have an analog spindle spindle output with the 7i76e, it's easier to set up and just seems to work better. I use S+D on the clearpath to 3krpms as well. DYN4 autotuning is terrible but if you tweak it yourself it works great as a spindle drive.

I suggest you use a 7i96 as the main card and 7i85 for the encoders like PCW said. With the DYN4, the step+direction is not a problem regardless of which card you use but it you want to use the alarm/enable/reset I/O with the drive you need to use something with sinking I/O (negative). So the 7i96 can handle that but if you have things like PNP sensors and such on the rest of the machine you'll probably want to use a 7i66 as well to get Positive inputs and extra outputs.

ok,
so I know its been a while, but after reading through all of this, there are a couple of thoughts
1. I am pretty convinved that ill get the 7i96 and the 7i85, along with my linear encoders.
2. I am not a programmer (Python) and dont claim to be, or an Electrical Engineer, just Mechanical.
3. I am a little nervous about spending the money on this and then not being able to set the Mesa card up properly and set the HAL file like it needs to be to work properly and read the encoders etc etc.
4. where would I find help on this?

ok... so where would be the first place to start. Obviously I order it and the various components, but from there, what do I do with the card. my limited understanding is that it needs to be flashed with firmware. how is that accomplished?

ok,
so I ordered my encoders they are on the way, in the mean time. i need to figure out what ALL I need in terms of hardware from Mesa.

I need to get the 7i96 and the 7i85 but is there anything else I am going to need to interface to my other hardware? or to interface these two cards to each other?

ok, so I ordered the cards and have them installed. now I need to flash the 7i96 correct? will I need to do anything with the 7i85? or just plug it into the 96?

You need to check to see that the power suply jumpers are set correctly for the db25 port, How they are set on the 7i85 needs to match how the port is set on the 7i96.