V0N_hydro
Member
I am used to using SFC in Schneider unity and we use the step.X bit in the logic to see if the step is active. We don't use parallel branches so only one step can be active at a time.
I have found in RSLogix I can simply toggle the STEP.X bit for any step. It seems dangerous if the PLC operates some outputs when a step is active because we are depending on other things to have happened in the previous steps, but if I accidentally CTRL+T in a ladder routine with the XIC STEP.X accidentally selected then the step becomes active (as well as the other step that was actually active) and the PLC operates the outputs accidentally.
Is there some setting to make it impossible to write to the STEP.X bits?
Anybody who uses SFC in Logix5000 how do you avoid this?
Thanks for any insights
I have found in RSLogix I can simply toggle the STEP.X bit for any step. It seems dangerous if the PLC operates some outputs when a step is active because we are depending on other things to have happened in the previous steps, but if I accidentally CTRL+T in a ladder routine with the XIC STEP.X accidentally selected then the step becomes active (as well as the other step that was actually active) and the PLC operates the outputs accidentally.
Is there some setting to make it impossible to write to the STEP.X bits?
Anybody who uses SFC in Logix5000 how do you avoid this?
Thanks for any insights