I will try to comment on your questions in order:
If the masks are placed [farther] apart where the timer has a chance to complete its cycle, then the sprayer will turn off until it sees the next one in its path.
It will turn off provided that the part is narrrow enough so that the prox no longer sees the part when the timer goes off. If Prox 1 still sees the part, with the current program, the sprayer will restart again for the same amount of time. If this happens, it can be prevented with some extra program steps. It all is inter-connected with the width of the part, the timer settings, and the speed of the conveyor, so impossible for me to see now how this part will operate.
On the second sensor once the mask enters its field of view it will stop operation and stay that way until the item is removed from its field. Once the item is removed from its field the conveyor will start up again.
This will only work successfully if the part is wide enough to allow the conveyor to stop BEFORE the mask moves out of Prox 2 range. If the part is relatively narrow, then the conveyor will coast far enough to move it out of Prox 2 range, causing the program to see a STOP, then a RESTART command (throwing the part off the end of the conveyor).
How wide is the mask, and how fast is the conveyor traveling in Feet per Minute?
On the relays. . What is really needed in essence? A relay that supplies 24v to i1 for power on and that's it?
The only relay you need is the safety relay, because your EZ512-DC-RC has relay outputs with dry (unpowered) contacts. The dry contacts can be used for the VFD commands, and also for the solenoid provided it does not use more than 2 Amps or 48 watts.
I'm a little lost on what to do with safety relays...
You said it had two contacts. Use one safety contact as an inline switch between your VFD "CM" terminal and the Q1-1, Q2-1, and Q3-1 terminals. Use the other as an inline switch between your +24 power supply terminal and Q4-1. This wiring will allow the safety relay to completely disconnect all Outputs when the E-Stop is pressed. (Wire the E-stop button to the saftey relay inputs so that its output contacts are held on until the E-stop is pressed). You do not need to disconnect the EZ Inputs, because the inputs do not perform any actions that result in potential or kinetic energy (unlike the Outputs), and the 24 VDC power to the inputs represent no safety hazard. That is all!
On the spray solenoid, utilizing 2 wires, a +24v and a ground (0v), when I connect this to the q4, would I wire 24v+ into the terminal 1 of q4 then the termainal 2 to one leg of the spray solenoid.
No, wire your +24 from your power supply to one contact of the safety relay, THEN from safety relay to Q4-1. From Q4-2, wire to the + side of your solenoid. Wire the - side of solenoid to the -24 of your power supply.
Note: those relays were for an earlier idea. I won't be using them. Actually I probably won't need relays as the plc is adequate enough right?
Yes, the interposing output relays were suggested before someone realized that your EZ had built-in relay outputs. (Most people now use transistor outputs). But again, make sure that your solenoid does not use more that 2 Amps of start-up current.
If you run thousands of parts through, the Q4 relay contact in the EZ will eventually wear out from switching on/off many times. You can then replace the EZ with a new one.
I ran your program in the simulator and it seems flawless...
I am glad you think so. I tried to make it do what you need, but be prepared for some surprises. Things in the real world hardly ever happen just as we would like, so keep your tweaking screwdriver and the duct tape handy! Depending on the mask width, conveyor speed and stopping time, you might need a 3rd prox at the end of the conveyor after Prox 2.
