gravitar
11-16-2007, 08:04 PM
Hello! This isn't CNC related but I admire how much you guys accomplish with PC hardware :) Anyway I'm hoping this will be a pretty simple one. I've been asked to come up with a way to display one of eight bitmap graphic images on a PC's screen from the logic in an Allen-Bradley ControlLogix controller. At first it was suggested that we get fancy and message it using Ethernet/IP, but the more I think about it, it makes more sense to just use hardwired discrete I/O. So what I'm looking for is a cheap module to hook up to a PC (PCI/ISA bus, even parallel or USB would be fine) that I will be able to poll in VB and display the appropriate image. My knowledge of VB is minimal at this point, but I've been looking for a good reason to learn and get better! Please give me your ideas.
Al_The_Man
11-16-2007, 08:21 PM
I believe I understand what you want to do, this would normally be achieved probabally by something like a Maple Graphic HMI, and communicate directly with AB port.
If you intend using a discrete IO module, 8 bits, then you could use a parallel port, configured for input? You may have to condition the signal to conform to 5v.
I am assuming you just need to trigger one of eight bit mapped images?
Al.
gravitar
11-16-2007, 08:37 PM
Yup, I have 8 image files to choose from and I need to binary select one of the eight.
to tell the rest of the story, this system has an A-B Versaview CE terminal connected. This is a VERY stripped-down thin client terminal.. It has the OS and HMI software in ROM and basically can't do much else. I was originally asked to do something with this versaview terminal but I think I would be wasting my time. PCs are cheap, I think a small I/O card should be cheap, and it shouldn't be too hard to program.
Connecting to the parallel port is fine, but I need to be able to bring 24VDC to it. 24V control is the standard that most control panels follow, and although 5V would probably be sufficient I need to conform to what everybody else is doing.
Al_The_Man
11-23-2007, 08:03 PM
Connecting to the parallel port is fine, but I need to be able to bring 24VDC to it. 24V control is the standard that most control panels follow, and although 5V would probably be sufficient I need to conform to what everybody else is doing.
I missed the latest answer somehow:confused:
but it should be relatively easy through the parallel port, the 24vdc AB output card could simply go to a custom mocked up board using common 2N35 etc opto isolators.
I make up a lot of custom made interfaces using a copper strip prototype board like Vero (not Vector), fast and effective.
Another idea would be to use a RS232 AB Serial interface module, if the PLC supports this type.
Al.