It would be more realistic to put the new NOT X5 "TANK-FILL FAILURE ON/OFF" switch contact on the rung after Rung 71, the F118 DOWN-UP Counter trigger. Then the TMX 2 timer will run, and Y1 TANK FILL will be ON. But F118 will not count, so the tank will not fill past 0%. Then after 5 minutes, the Y6 LOW LEVEL alarm should go ON.
I am now calling the F118 counter a "DOWN-UP" Counter, not a "UP-DOWN" counter as listed in the manual. I think it is a culture difference. I suppose that in Japan, their timers, tanks, and devices always start out to be FULL first, and then go to EMPTY. In the US, ours start out EMPTY and have to be FILLED before they can be used.
In the US Allen Bradley RSLogix UP-DOWN Counter, to make it count up to 102, you set the Counter Preset to 102 and activate the UP trigger. It starts at 0 and counts to 102, then stops. If the DOWN trigger is activated, it counts back down to 0. If you should set the Preset to 0, and then give it an UP trigger, it would immediately turn on its DONE bit and not count, because it is already at the preset of 0.
For the F118 to first count UP, you have to give it a Preset of 0. For the F118, the Preset Value gets moved to the Elapsed Value, where for RSLogix, the Preset and Elapsed (Accumulator) are always 2 separate values. The Preset never changes and never gets written over by the counter. On the other hand, the F118 Function is really made to start at the Preset of xxx and count down to 0, then back to xxx. It is a DOWN-UP counter, not a UP-DOWN counter.
I am now calling the F118 counter a "DOWN-UP" Counter, not a "UP-DOWN" counter as listed in the manual. I think it is a culture difference. I suppose that in Japan, their timers, tanks, and devices always start out to be FULL first, and then go to EMPTY. In the US, ours start out EMPTY and have to be FILLED before they can be used.
In the US Allen Bradley RSLogix UP-DOWN Counter, to make it count up to 102, you set the Counter Preset to 102 and activate the UP trigger. It starts at 0 and counts to 102, then stops. If the DOWN trigger is activated, it counts back down to 0. If you should set the Preset to 0, and then give it an UP trigger, it would immediately turn on its DONE bit and not count, because it is already at the preset of 0.
For the F118 to first count UP, you have to give it a Preset of 0. For the F118, the Preset Value gets moved to the Elapsed Value, where for RSLogix, the Preset and Elapsed (Accumulator) are always 2 separate values. The Preset never changes and never gets written over by the counter. On the other hand, the F118 Function is really made to start at the Preset of xxx and count down to 0, then back to xxx. It is a DOWN-UP counter, not a UP-DOWN counter.
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