Exercise 3 Critique
Rung 001: You have more instructions than you need. B3/0 XIC and C5:0/DN XIO are all you need here to Start and Stop Pump 1 O:2/1.
Rung 004: You used two counters C5:0 and C5:1 for Flowmeter 1, where one would work just as well. I think the intent was to use ONE Up/Down counter for Tank Level, with Flowmeter 1 (filling) controlling the Count UP, and Flowmeter 3 (draining) controlling the Count DOWN. In the later advanced exercises, Flowmeter 2 and Pump 2 comes into the picture, so keep that in mind while setting up your program framework. Now you may be saying "What does the next Advanced Exercise have to do with this one"? The answer is that it is a simulation of what often happens in the real world. You have the specifications for a programming job, and you do it, but just as you finish, someone comes in and says, "we need to add another pump and flowmeter for another ingredient to be mixed into the batch." Now if you have anticipated this event, you will easily be able to add Pump 2 into your logic without starting completely over from scratch. (or NOT in your case!)
Rung 007: You used "Pump 1 OFF" to start the Mixing Timer. Really, the mixing cycle should start when the Tank Level is at 90% Full. Logically the mix start has nothing to do with Pump 1, although it works in your program because Pump 1 gets cut off at the end of the fill cycle. Later when you add Pump 2, your method will no longer work correctly without modifications (see Rung 004 critique). With TWO pumps filling, each pumping different (variable) amounts, you cannot say that Pump 1 will shut off just as the tank reaches the required fill level. It may be that Pump 1 shuts off long before Pump 2 finishes up the filling cycle, or vice-versa.
Rung 008: You should reset the Mixer Timer T4:0 before Pump 1 starts, maybe when Pump 3 stops during the pervious cycle.
Rung 010: Again you have more instructions than you need. B3/0 XIC and T4:0/EN XIC are all you need here to Start and Stop Mixer 1 O:2/0.
Rung 013: You have Pump 2 and Heater O:2/4 turning on the Run Light, although you do not turn on either Pump 2 or the Heater anywhere in your program, and the official instructions do not mention either one (for this exercise). Here you are trying to anticipate what may be coming down the road, but not doing it correctly.
Rung 001: You have more instructions than you need. B3/0 XIC and C5:0/DN XIO are all you need here to Start and Stop Pump 1 O:2/1.
Rung 004: You used two counters C5:0 and C5:1 for Flowmeter 1, where one would work just as well. I think the intent was to use ONE Up/Down counter for Tank Level, with Flowmeter 1 (filling) controlling the Count UP, and Flowmeter 3 (draining) controlling the Count DOWN. In the later advanced exercises, Flowmeter 2 and Pump 2 comes into the picture, so keep that in mind while setting up your program framework. Now you may be saying "What does the next Advanced Exercise have to do with this one"? The answer is that it is a simulation of what often happens in the real world. You have the specifications for a programming job, and you do it, but just as you finish, someone comes in and says, "we need to add another pump and flowmeter for another ingredient to be mixed into the batch." Now if you have anticipated this event, you will easily be able to add Pump 2 into your logic without starting completely over from scratch. (or NOT in your case!)
Rung 007: You used "Pump 1 OFF" to start the Mixing Timer. Really, the mixing cycle should start when the Tank Level is at 90% Full. Logically the mix start has nothing to do with Pump 1, although it works in your program because Pump 1 gets cut off at the end of the fill cycle. Later when you add Pump 2, your method will no longer work correctly without modifications (see Rung 004 critique). With TWO pumps filling, each pumping different (variable) amounts, you cannot say that Pump 1 will shut off just as the tank reaches the required fill level. It may be that Pump 1 shuts off long before Pump 2 finishes up the filling cycle, or vice-versa.
Rung 008: You should reset the Mixer Timer T4:0 before Pump 1 starts, maybe when Pump 3 stops during the pervious cycle.
Rung 010: Again you have more instructions than you need. B3/0 XIC and T4:0/EN XIC are all you need here to Start and Stop Mixer 1 O:2/0.
Rung 013: You have Pump 2 and Heater O:2/4 turning on the Run Light, although you do not turn on either Pump 2 or the Heater anywhere in your program, and the official instructions do not mention either one (for this exercise). Here you are trying to anticipate what may be coming down the road, but not doing it correctly.
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