C
Hi All Back to the hardware world. I have a project with my day job employer to do a terminal board to translate from the DIO 48 ttl I/O to industrial levels. This is part of a critical automation project so it should happen and happen soon. They are debating whether to offer this as a product or release it to LPLC. Either way we eliminate a roadblock. I had to include the option of selling it to get approval for the project. Right now, I have to focus on making it. To keep it as simple as possible, I looked at a few typical projects for IO count and came up with the fact that most of what we do uses about twice as many inputs as outputs. I am looking at 32 in, 15 out for the DIO 48 or 16 in 7 out when used with a DIO24 or single 8255 card.. One output in any case is used as an output enable as the 8255 pins are indeterminate until programmed and startup safety demands outputs off until valid. It should be usable with two DIO 24 cards also, you would want to control initialization order. This conveniently uses a single DP8311 and 8 quad optoisolators. I am still pondering adding photo darlingtons to the outputs for completely isolated I/O. We don't need this for our application and it raises the connector count and cost. No point in having isolated outputs if the commons are all bussed together, perhaps groups of 4 or 8 is a good compromise. I haven't hit on a way to make it din rail mountable that wouldn't cost too much in low volume, but I'll be thinking about it. Suggestions, as always are welcomed. just thought I'd pass along the good news. Regards cww _______________________________________________ LinuxPLC mailing list [email protected] http://linuxplc.org/mailman/listinfo/linuxplc