1 input 1 output

[Setht694]

How can I use 1 button and 1 light using only b3

 

[Ken Roach]

Welcome to the PLCTalk forum community !

Your reference to "B3" suggests you are probably using an Allen-Bradley SLC-500 or MicroLogix controller. That is the default Data Table file that holds "bit" data for use in user control programs.

And the very brief description of your challenge suggests that you're in a PLC programming class with a lesson on "flip flop" or latching logic.


The forum policy for students is both "please ask a complete question with details and context", as well as "show your work so far".

Every one of us started out one day looking at the graphical representations of coils and contacts and learning how it translated into logic. There's nothing wrong with looking for help on the fundamentals of the topic.

So do your best to ask a more complete question (and have a look at the PLC Tutotial link at the top of the page). And welcome to the PLCTalk forum community !

 

[Operaghost]

B3 sounds like you are using a Rockwell/Allen-Bradley PLC-5, SLC 500, or MicroLogix. If this is not correct, let us know what you are actually using. As Ken mentions, this sounds like a classroom assignment. Let's make sure we cover some basics before we dig too deeply.

First, B3 is a file that is chock full of individual bits that you can use. There are hundreds, even possibly thousand of bits available in that file. But, these bits are strictly internal to the controller. They do not have any direct connection to a real world pushbutton or output light. But let's assume you don't mean a physical button and light.

Inside of the B3 file you will find up to 256 words (1,000 in the PLC-5) numbered from 0 to 255. They are addressed as B3:0 though B3:255. However, by default, there is just one word, B3:0. Any additional words are created manually, or created as you use them.

Each word is made up of 16 bits, where each is identified as 0-15. So the very first bit in B3 would be identified as B3:0/0 and the very last bit would be identified as B3:255/15. That allows for a total of 4096 bits just in the B3 file. Plus you can make more "B" type files. I could make "B25" and that would buy me up to 4096 additional bits.

All you have to do, is pick which bit to use for your button, and which bit to use for your light. Note that some MicroLogix may have different limits as to how many files or words are available.

Now, if you can more clearly explain what it is you are trying to accomplish, and show us what you have so far. We won't do the work for you, or give you the answer straight away. But we will try to help guide you to come up with the right answer.

OG

 

[Setht694]

I need to make a simple program in my class. I can use 1 input for my button 1 output for the light. The button needs to toggle the light. No single shot instructions. Only b3 0/0 one time. And yes I'm using rs logix500

 

[Setht694]

B3 sounds like you are using a Rockwell/Allen-Bradley PLC-5, SLC 500, or MicroLogix. If this is not correct, let us know what you are actually using. As Ken mentions, this sounds like a classroom assignment. Let's make sure we cover some basics before we dig too deeply.

First, B3 is a file that is chock full of individual bits that you can use. There are hundreds, even possibly thousand of bits available in that file. But, these bits are strictly internal to the controller. They do not have any direct connection to a real world pushbutton or output light. But let's assume you don't mean a physical button and light.

Inside of the B3 file you will find up to 256 words (1,000 in the PLC-5) numbered from 0 to 255. They are addressed as B3:0 though B3:255. However, by default, there is just one word, B3:0. Any additional words are created manually, or created as you use them.

Each word is made up of 16 bits, where each is identified as 0-15. So the very first bit in B3 would be identified as B3:0/0 and the very last bit would be identified as B3:255/15. That allows for a total of 4096 bits just in the B3 file. Plus you can make more "B" type files. I could make "B25" and that would buy me up to 4096 additional bits.

All you have to do, is pick which bit to use for your button, and which bit to use for your light. Note that some MicroLogix may have different limits as to how many files or words are available.

Now, if you can more clearly explain what it is you are trying to accomplish, and show us what you have so far. We won't do the work for you, or give you the answer straight away. But we will try to help guide you to come up with the right answer.

OG

need to make a simple program in my class. I can use 1 input for my button 1 output for the light. The button needs to toggle the light. No single shot instructions. Only b3 0/0 one time. And yes I'm using rs logix500

 

[drbitboy]

See the other thread you started.