C
Curt Wuollet
Hi Bill and all
The initial I/O scheme that I am doing will be Modbus/TCP and can be implimented in user space and run without root permissions. Almost anything else except serial protos will need access to irqs and ports. You can usually relinquish root permissions. You will need kernel mode drivers
in some cases, but, they can be minimal like Bill sez. Another approach I like is to do the direct
hardware access under RTLinux. Actually, I like the idea of good old Ethernet for all I/O for reasons below and cost. Modbus/TCP is the
closest thing to an open fieldbus protocol I've found so far, everything else I would have to join something or buy somthing and the hardware is vastly overpriced. Unfortunately, not too
many I/O vendors support Modbus/TCP and the only other Ethernet standard that I've seen, ControlNet seems to be run by the same set of control freaks that run ODVA. Modicon may loosely control Modbus/TCP but they are trying a lot harder than anyone else by publishing it for free with example code. I don't see any licensing or
intellectual property problems with it.
Curt Wuollet
Wide Open Technologies
The opinions expressed ARE the opinions of the company, it's the only benefit I get.
The initial I/O scheme that I am doing will be Modbus/TCP and can be implimented in user space and run without root permissions. Almost anything else except serial protos will need access to irqs and ports. You can usually relinquish root permissions. You will need kernel mode drivers
in some cases, but, they can be minimal like Bill sez. Another approach I like is to do the direct
hardware access under RTLinux. Actually, I like the idea of good old Ethernet for all I/O for reasons below and cost. Modbus/TCP is the
closest thing to an open fieldbus protocol I've found so far, everything else I would have to join something or buy somthing and the hardware is vastly overpriced. Unfortunately, not too
many I/O vendors support Modbus/TCP and the only other Ethernet standard that I've seen, ControlNet seems to be run by the same set of control freaks that run ODVA. Modicon may loosely control Modbus/TCP but they are trying a lot harder than anyone else by publishing it for free with example code. I don't see any licensing or
intellectual property problems with it.
Curt Wuollet
Wide Open Technologies
The opinions expressed ARE the opinions of the company, it's the only benefit I get.