Glenn,
I hope I'm not interfering with the learning process. I'm trying to define the process with more accuracy.
My version of operations is a little different than yours, it organizes the processes into more steps than your description. If this is not how your process works disregard my effort, or make it clear what does need to happen.
1. At rest with the power on or off, the air cylinder must lock the lid closed.
2. Purge; Operator presses the amber purge push button. If the lid prox closed is made and the stop button input is on the amber purge indicator will light, note: when the "red lid open" light is on the amber purge indicator will turn off. Note: if the control power input is not made (a liberty I took to make the process correct in my mind) the purge cycle will stop and the machine will go to step 1 (at rest). If the lid closed input opens before the lid lock cylinder is actuated the machine will go to step 1 (at rest)
2a. Purge w/nitrogen. A timer starts at the beginning of the purge cycle that opens the nitrogen valve for 12 seconds.
2b. Purge w/scrubber. The same timer from 2a continues to time, and as the time elapses from 2 seconds to 14 seconds the scrubber valve opens.
2c. Purge w/lid open. The same timer from 2a continues to time, at 16 seconds the timer will acutate the lid lock cylinder to the "open" position. The lid lock cylinder will remain in the "open" position until further notice. I have taken the liberty of making this valve a bistable control valve. The red indicator will turn on when the lid closed limit is not made.
3. Charge; Operator closes lid, (note: the red lid open light will turn off when the lid closed limit switch and the lid close cylinder prox are made, another liberty I took) and he presses the green lighted pushbutton "charge solids", the lid lock cylinder close is activated.
3a. If the lid closed limit switch and the lid lock cylinder prox and the control power input and the green lighted push button are made then the green charge indicator will light. The green indicator will remain lit as long as the lid closed and cylinder prox and control power input are made.
3b. If the green light is on (see conditions above) then a timer starts and the nitrogen sol valve opens again (see 2a) close the nitrogen valve at 32 seconds
3c. After two seconds the scrubber valve opens, close the scrubber valve at 34 seconds.
3d. At 12 seconds open the vibrator valve, close the valve at 32 seconds.
3e. At 12 seconds open the dump valve, close the valve at 34 seconds.
3f. At 34 seconds activate the lid lock cyinder "open" to open the lid. note at this point the cylinder prox will not be made and the green inicator will turn off.
At this point your description does not make sense to me.
(Operator can now open lid to Inspect or Add more Charges if needed), Once Lid Limit Switch is made go to IDLE Stage.
6. STOP OPERATIONS: Red Pushbutton with 1 set of NO contacts to stop all operations when pushed so all valves will close, If Hopper Lid LS is made SV Air lock will remain engaged, Timer 30 seconds, after Timer DN, turn On Red PL (Unlock Dome) and Disengage Lid SV Air Cylinder (To Allow For Inspection), Start Timer 5 minutes, after Timer DN or once lid Limit Switch Is made Engage Lid SV Air Cylinder, go to IDLE STAGE.
Questions; Does he press the green button at this point to recycle the machine? Also perhaps a better name for your stop button is a "halt process" What do you want to happen after the stop button (or halt) is pressed if there is a power interruption at this point?
