C
Hi All
Attempting to resurrect my PC104 PLC project now that the dust has settled a bit. I've got a question for those folks who have dug a little bit and pried details from the manufacturers. As you may remember. I was proposing the ISA bus as exemplified on the PC104 connector as the module bus for my PLC backplane. The reasons are many, it is well understood, it is "hackable" by persons who aren't hardware professionals and it is inexpensive to interface to with garden variety TTL OTS components.
The question is: What widths and speeds are used in industry equipment? I've seen some, for example, Wago/Beckhoff stacks I/O with very few pins, most I/O modules seem to have narrow busses, I'm reconsidering the decision before I charge off in that direction again. And please recall that I'm talking about simple IO here. Complex functions, frame grabbers high speed analog, etc. would be handled by stacking cards on the PC104+ bus. I'm not prying for secrets here, I just want to have the best throughput available in a PLC form factor.
And yes, I know the move is on to obsolete ISA, but thirty years from now it will still be easy to learn and work with.
Regards
cww
P.S. It occurred to me that we may have readers who have no idea what I am talking about since it's been more than a year since the original thread. This past year has been rather too traumatic for me to deal with side projects, but I've finally stabilized things to the point where I can rise above survival.
Anyways, here's a link to the original discussion with some very good points raised by folks familiar to us all.
http://www.control.com/1012600615/index_html
Attempting to resurrect my PC104 PLC project now that the dust has settled a bit. I've got a question for those folks who have dug a little bit and pried details from the manufacturers. As you may remember. I was proposing the ISA bus as exemplified on the PC104 connector as the module bus for my PLC backplane. The reasons are many, it is well understood, it is "hackable" by persons who aren't hardware professionals and it is inexpensive to interface to with garden variety TTL OTS components.
The question is: What widths and speeds are used in industry equipment? I've seen some, for example, Wago/Beckhoff stacks I/O with very few pins, most I/O modules seem to have narrow busses, I'm reconsidering the decision before I charge off in that direction again. And please recall that I'm talking about simple IO here. Complex functions, frame grabbers high speed analog, etc. would be handled by stacking cards on the PC104+ bus. I'm not prying for secrets here, I just want to have the best throughput available in a PLC form factor.
And yes, I know the move is on to obsolete ISA, but thirty years from now it will still be easy to learn and work with.
Regards
cww
P.S. It occurred to me that we may have readers who have no idea what I am talking about since it's been more than a year since the original thread. This past year has been rather too traumatic for me to deal with side projects, but I've finally stabilized things to the point where I can rise above survival.
Anyways, here's a link to the original discussion with some very good points raised by folks familiar to us all.
http://www.control.com/1012600615/index_html