godfrey
Member
My boss and I are in disagreement as in how to put a SCADA map into our PLC programms. We provide PLC based control cabinets with door mounted OITs for a variety of processes. There is usually a separate integrator who will provide a SCADA computer to which our PLC will be linked.
The SCADA must read status bits and process variables and also write bits and setpoints to our PLC. Here is where we disagree:
I want to let the SCADA write to the same registers that my OIT writes to. A SLC 500 example would be: N7:0 is the flowrate setpoint. There is a numeric data entry button on the OIT addressed as N7:0 for this. If SCADA writes to N7:0 or if the OIT button writes to N7:0 it works.
My boss says, create a separate SCADA map file like N47. Let SCADA write to the N47 file only. Then I program the N47 addresses to write to N7:0 and other like addresses. WHY??? Because if the integrator's map is off, he will be writing to a different address and screw things up. My boss wants a disable bit in front of every line of our code in the SCADA map so that I can prove that errors are due the map being off.
Is there any merit to this? How do you do it?
The SCADA must read status bits and process variables and also write bits and setpoints to our PLC. Here is where we disagree:
I want to let the SCADA write to the same registers that my OIT writes to. A SLC 500 example would be: N7:0 is the flowrate setpoint. There is a numeric data entry button on the OIT addressed as N7:0 for this. If SCADA writes to N7:0 or if the OIT button writes to N7:0 it works.
My boss says, create a separate SCADA map file like N47. Let SCADA write to the N47 file only. Then I program the N47 addresses to write to N7:0 and other like addresses. WHY??? Because if the integrator's map is off, he will be writing to a different address and screw things up. My boss wants a disable bit in front of every line of our code in the SCADA map so that I can prove that errors are due the map being off.
Is there any merit to this? How do you do it?