1771-spi

does anybody used 1771-SPI before? or any info on SPI Protocol?

Ohhh... the horror.. the pain... Your best bet is reading the AB Manuals for that card, and asking (begging) the other equipment manufacturer to give you a document on what parts of it they support.

I've used it, it works... but never again.

You can buy a copy of the actual protocol information for a mere $2500 from someone named Jennifer here:
http://www.plasticsmachinery.org/literature.html

yeah, i've seen the horror and felt the pain...was able to see the connected devices but it keeps timing out on me comm wise...was able to send one instruction and receive one status eventually after 8 long hours of hair pulling. any tricks?

No... no tricks... I just poked and prodded it for a week or three untill I finally got it to communicate with a few chillers. Mostly, because the chiller manufacturer had excellent documentation on what information they provided/expected, and how it was layed out.

Ultimately, that is what you need to know, how the end device formats and expects it's blocks to be formatted.

got it going...have to play with the pullup resistor values