Plss help me.big problem for me

[Lancie1]

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.

 

[Lancie1]

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.

CORRECTION: the RSLogix Counter does not actually stop counting when it reaches the Preset Value. It turns on the DONE bit, but if triggered, will actually keep counting up to the maximum allowed counter value (32767). In most cases, the DONE bit is used to perform some action and also to either inhibit the counter trigger, or to reset the counter to 0.

 

[fidamin]

Owh..so that is two different between US's ultrasonic sensor and Japan's ultransonic sensor

 

[Lancie1]

Yes, our tanks are always half-empty, never half-full.

 

[Jessua]

How to make it stop after 102 %?I mean the high limit level safety turn off.

 

[Lancie1]

How to make it stop after 102 %? I mean that the high limit level safety turns off (and it recycles by draining the simulated tank).

Yes, that is the way I set this student exercise to work. Study the logic and see if you can figure out how to make the simualtor stop at any time. HINT: it is controlled by the 1-second timer and the F118 DOWN-UP Counter.