Pulse Challenger

dandrade

Member
D
Join Date
Jan 2004
Posts
374
I front lithe challenge, this moment get large code for implemented.

The code must be prepared to work as limited PLC (Relay controls), two alternatives to make

1)Code using FB-Function Blocks and Logic gates (AND,OR,XOR,NOT)
2)Ladder code

Note, not have counter with ENABLE. Only, INPUT and RESET
The graphic signals: A/B is input and V/counter the result.


Click to large image
 
Looks to me like you would just use A and B (rising edge) = count 1.

In other words A can do what it wants but it be high and have rising edge B to count.
BUT
The picture left out a detail I think may be relevant. It looks like A should transition from HIGH to LOW then HIGH before the next count is made. WAIT...use rising edge A to latch a bit0, BIT0 and rising edge B = count and unlatches BIT0...one shot would require A to transition to rising edge A to relatch bit before next count.
 
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rsdoran said:
Looks to me like you would just use A and B (rising edge) = count 1.

In other words A can do what it wants but it be high and have rising edge B to count.
BUT
The picture left out a detail I think may be relevant. It looks like A should transition from HIGH to LOW then HIGH before the next count is made. WAIT...use rising edge A to latch a bit0, BIT0 and rising edge B = count and unlatches BIT0...one shot would require A to transition to rising edge A to relatch bit before next count.
Click to expand...

Possible put graphic?
Yes, easy result V === AND Rising (Have the block)

Have Latch,Flip-Flop RS-Function Block

Same, the result for counter is equivalent Flip-Flop D
Please, use terms transition positive ad negative, for less confusing.
 
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Yes!!

Yes!
Rsdoran, you cheat make snall code: Only 2 gates + inverter + Flip Flop RS + Counter. Is 5 blocks!!!

Understand you code, some the idea signals.
Its have others guys, to get result... good luck.

 
Actually I think there are fallacies in what I offered. I think I did not see it properly. Either one can be high but there must be transitions from both before a count is made. I am not sure this picture of AB logic is precise either (no way to test) but I think it makes both A and B have to have transitioned after a count and be HIGH to obtain the next count.
count1.jpg


NOTE: I have a new laptop without most software installed, I went to AB and downloaded the free version of RSLogix500. I see I messed up on my addresses the OSR's should be B3/0 and B3/2 and the transition bits B3/1 and B3/3.
 
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Home sick today so I thought I'd try this with relays. It assumes that A has to pulse at least onse before B can trigger the V output on the rising edge. My interpretation of Dandrade's timing diagram may be wrong.
Thank goodness for PLCs or even smart relays.
A1, B1 are supposed to me one shots of A, B on their rising edge. C1 memorizes a single pulse of A.
This sucker will be noisy if it even works.

The normally closed A contact on rung 011 should be normally open.

dandrade1.jpg

The normally closed A contact on rung 011 should be normally open.
 
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It looks like simple gating logic to me. A increments the counter at a false to true transition, but ONLY when B (the gate signal) is ON. The "V" pulse seems to be triggered the false-to-true transition of B alone, although, in the diagram, A is always shown as ON when B makes the transition. IOW, the behavior of the "V" pulse may or may not be affected by the state of A... :confused:

🍻

-Eric

P.S. Phil's newly found translator was no help this time... ;)
 
A is always shown as ON when B makes the transition.
Click to expand...
That is what I first thought, but the example even though it has highlights did not fully explain what has to happen. I think I changed my approach because in the example it shows transitions for A before another count is made, I guess I "assumed" both should transition..if A does not have to transition then you could remove the A Transition bit code.
 
Common situation: Counting of products in Convervoy. Only while moving and not recount the part after stops

RSdoran, second contact in line to counter B3/1 dont see activation? Is unique..?

Jstolaruk, what this software? Dense It symbols, not clear.. to later time study you code
Put draw code smaller code Function Blocks:

codesignals9dc.png
 
Dandrade, its not software, its hard wired relays.

The vertical lines on either side represent power. Each horizontal circuit is called a rung. The circle symbol is a relay coil, the others are normally open and normally closed contacts driven off their respective coils.

Based on your drawing, I obviously designed it without knowing enough about the project goals.
 
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