cardosocea
Member
It surprises me that this isn't common rather than being something we fight about.
The reality is that having this information in a clearly visible format is priceless for maintenance and even operators. Granted, there's an element of education required for operators, but we really should strive to end the days of "looking in the plc" for what's stopping a machine. The process industry has as a standard a display of interlocks precisely for this. Somehow machinery doesn't think it's necessary.
I agree to the extent that most programming languages are **** at relaying the information to non-programmers. SFC and if used with process blocks FBD (or the Siemens CFC) along with a strict variable naming standard is a lot better than some traditional flowcharts. Remember that it's tricky to display parallel or selection tasks in flowcharts. In SFC, this is accounted and takes little to explain that 2 lines is parallel and 1 line is selection.
I'm doing that now with the process guys and they not only love it, but want it for operations and as the documentation of the process recipe.
The reality is that having this information in a clearly visible format is priceless for maintenance and even operators. Granted, there's an element of education required for operators, but we really should strive to end the days of "looking in the plc" for what's stopping a machine. The process industry has as a standard a display of interlocks precisely for this. Somehow machinery doesn't think it's necessary.
Diagrams like this should communicate to non-programmers what the expected operation of the equipment/process will be. It should be used as an engineering document to tell others how to program it, and/or be used in conjunction with FAT/SAT testing to ensure that ladder logic you wrote does what you expect it do.
I agree to the extent that most programming languages are **** at relaying the information to non-programmers. SFC and if used with process blocks FBD (or the Siemens CFC) along with a strict variable naming standard is a lot better than some traditional flowcharts. Remember that it's tricky to display parallel or selection tasks in flowcharts. In SFC, this is accounted and takes little to explain that 2 lines is parallel and 1 line is selection.
I'm doing that now with the process guys and they not only love it, but want it for operations and as the documentation of the process recipe.