Created Date: February 24,2007

Created by: Steve Bailey

PLC inputs that come from a C-More or any HMI panel are directly written by the C-More. As long as nothing else writes to the same memory location, they will maintain their states.

If the C-More writes to X memory and there is an input module present that writes to the same X memory location, the signal from the input module will prevail. If there is no module writing to the X memory location, the signal from the C-More will work.

If a pushbutton object on a C-More screen is configured as momentary, when the operator touches the object, the C-More writes a value of 1 to the memory location associated with the tag. When the operator takes his finger off the object, the C-More writes a value of 0 to the memory location associated with the tag.

If a pushbutton object is configured as toggle, when the operator touches the object, the C-More first reads from the PLC the current state of the memory location associated with the tag, then it writes the opposite state back to the same memory location.

Some protocols (Modbus is an example) won't permit writing to input memory. In that case, you have to write to some other location.

Created Date: February 27,2007

Created by: jackson

If your concern is that a bit input from Cmore may be off in Ladder rung 1 but on in Ladder rung 1000, I don't think this can occur.

If you look in the PLC user manuals, you will see a description of the scan architecture. The communications get serviced in a different area than logic scan, so a bit input from Cmore should be consistent throughout the entire logic scan within 1 given scan.