Homework Help, Someone help please!

Our instructor never taught us how to use the internal address or how to interlock. Any help would be appreciated! Thanks in advance.



-In vehicle there is open (PB1) and Stop (PB2) PB1 is a momentary push button and PB2 is a normally closed switch
-You need a seal in circuit made from internal addresses so PB3 won't be sealed in as well.
-PB3 is inside of the garage and will control open and stop and is a maintained switch.
-PB4 is for close and stop and is a maintained switch
-PB5 is used to close and stop the door and is a toggle switch
-(2) normally closed limit switches LS Top and LS Bottom are used to stop the door when it reaches the top and bottom of the door
-When the door is opening a green light comes on saying the driver can come in.
-A photo electric switch (normally closed) is used to detect if something blocks the door; if so it stops the door
-When the car pulls in far enough a normally closed photo switch detects it and turns on a red light. (green and red light should have interlock)
-The green light will only shut off if the car is in the right place
-Use a timer to turn the red light off after 10 seconds.
NOTE: You will need to use internal addresses
PB1 = I:0/0
PB2 = I:0/1
PB3 = I:0/3
PB4 = I:0/4
PB5 = I:0/6
Door open motor = O:0/0
Limit switch top = I:0/2
Limit switch bottom = I:0/7
Photo switch at door bottom = I:0/8
Door Close motor = O:0/1
Photo switch for car position = I:0/9
Green light = O:0/3
Red light = O:0/2

Welcome to the Forum:

What do you need help with exactly? We will all help, but we wont do the project for you. You wont learn anything that way
Best thing to do is start the project and when you get stuck, come back here, post your program (zip it first) and ask questions specific to help you get "over the hurdle". That way you get the help you need and learn at the same time.
It is also best to give as much info about the PLC equipment you are using as possible. That helps us answer properly.

I don't know how to do the internal bit I might have the interlock down. Also if you guys could check my program over and possibly tell me what I need to fix to get it right, that would be great.

I will upload it shortly.

SmokingGun said:

Our instructor never taught us how to use the internal address or how to interlock.

Click to expand...

It's hard to believe you've got a homework about something you've not been taught.
Anyways, the internal (auxiliary) bits are addressed as B:word/bit, words being 16-bit long. They are being used in a way similar to I/O bits.
Interlock, in general, is just using a device status to allow certain action on another device.

SmokingGun said:

-When the door is opening a green light comes on saying the driver can come in.

Click to expand...

Opening or completely open?

SmokingGun said:

A photo electric switch (normally closed) is used to detect if something blocks the door; if so it stops the door
-When the car pulls in far enough a normally closed photo switch detects it and turns on a red light.

Click to expand...

"Normally closed" photoelecrtic switches are usually referred as "Dark-On".

SmokingGun said:

-Use a timer to turn the red light off after 10 seconds.

Click to expand...

10 seconds after what?
After the light activation or after the car leaves the overrun sensor?

SmokingGun said:

NOTE: You will need to use internal addresses

Click to expand...

Sure you will.
It is important, however, to know whether you are allowed to use Latch/Unlatch instructions or must use coils only.

Sergei Troizky said:

It's hard to believe you've got a homework about something you've not been taught.
Anyways, the internal (auxiliary) bits are addressed as B:word/bit, words being 16-bit long. They are being used in a way similar to I/O bits.
Interlock, in general, is just using a device status to allow certain action on another device.


Opening or completely open?
--While it is opening and open

"Normally closed" photoelecrtic switches are usually referred as "Dark-On".
--Thanks, good info.

10 seconds after what?
After the light activation or after the car leaves the overrun sensor?
--After activation

Sure you will.
It is important, however, to know whether you are allowed to use Latch/Unlatch instructions or must use coils only.

Click to expand...

--I think he wants coil use only.

Here is what I have so far.--- Well my winzip trial expired and I am on my way to school I will upload when I get home tonight or tomorrow while I am at work. Thanks for the replies so far.

SmokingGun said:

--I think he wants coil use only.

Here is what I have so far.--- Well my winzip trial expired and I am on my way to school I will upload when I get home tonight or tomorrow while I am at work. Thanks for the replies so far.

Click to expand...

Ok I am sure everything is not correct but I think I have a pretty good start. Please check over my program note what corrections I would need to make (hint?) you don't have to tell I would like to figure it out. Please check my Bit and make sure I did that right and I don't think I interlocked them but I will work on that tomorrow. (hint for the interlock)

Revised

Would some member open the "Final Project.RSS" file and print it (select the Program File only in Report Options) to a PDF file, please? Then we could all see it.

--I think he wants coil use only.

Click to expand...

At last, we have an intelligent, experienced instructor.

Here you go

Thanks, Bernie.

First off, I see that the physical PB2 is a N.C. pushbutton, so therefore the first rung instruction PB2 XIO should really be a XIC instruction (a common beginner error).

There are many other errors. On Rung 001, no seal-in contact for B3:0/1 is NOT needed, because:

PB3 is inside of the garage and will control open and stop and is a maintained switch.

Click to expand...

"Maintained" switches (as opposed to Momentary Switches) stay ON until turned OFF.

Smoking, you really should add a descriptions for B3:0/0 and B3:0/1. What are they, how do they work, what do they do? While adding a description for B3:0/1, you may realize that you do not really need it - you can control the motors directly with a maintained-contact switch.

Here is a better-organized list of your PLC I/O addresses:

NOTE: You will need to use [the following] internal addresses:
I:0/0 = PB1 Open Door, NO momentary-contact
I:0/1 = PB2 Stop Door, NC momentary-contact
I:0/2 = Door Limit Switch Top, NC
I:0/3 = PB3 Open and Stop, maintained-contact
I:0/4 = PB4 Close and Stop, maintained-contact
I:0/5 = ?? (Spare)
I:0/6 = PB5 Close and Stop, momentary-contact
I:0/7 = Door Limit Switch Bottom, NC
I:0/8 = Photo Switch at Door Bottom, NC
I:0/9 = Photo switch for Car Position, NC

O:0/0 = Door Open Motor
O:0/1 = Door Close Motor
O:0/2 = Red Light (Car Clear of Door, off after 10 seconds)
O:0/3 = Green Light (Door Opening, Car not Parked)

Click to expand...

Lancie1 said:

Thanks, Bernie.

First off, I see that the physical PB2 is a N.C. pushbutton, so therefore the first rung instruction PB2 XIO should really be a XIC instruction (a common beginner error).

There are many other errors. On Rung 001, no seal-in contact for B3:0/1 is NOT needed, because:
"Maintained" switches (as opposed to Momentary Switches) stay ON until turned OFF.

Smoking, you really should add a descriptions for B3:0/0 and B3:0/1. What are they, how do they work, what do they do? While adding a description for B3:0/1, you may realize that you do not really need it - you can control the motors directly with a maintained-contact switch.

Here is a better-organized list of your PLC I/O addresses:

Click to expand...

Thanks for the help so far. I will try to make some corrections when I get off of work. He told us to use the bits to seal the circuit and he assigned us all of the inputs and outputs in that order. It is just a little harder to get because this is a microcontroller/PLC class and we spend 10 weeks on MC's and 1 week learning PLC's then 2 weeks doing labs then we get this.

Alright Lancie1 if you could check this over or if someone else could I would appreciate it. Thanks for your time and help. Also as you can see I couldn't figure out how to put it in pdf can you do it in RSLogix? I have all the logic shown.

I made it a word file and it was 400kb so I zipped it and it is finally able to upload.

Also let me know if the light is "interlocked"

If you can zip the RSS file I'll create the PDF. But check out CutePDF. It's free.

bernie_carlton said:

If you can zip the RSS file I'll create the PDF. But check out CutePDF. It's free.

Click to expand...

Thanks for the info! That was easy.

Ok take a look at this.

SmokingGun said:

-When the car pulls in far enough a normally closed photo switch detects it and turns on a red light. (green and red light should have interlock)

Click to expand...

I still don't see this requirement in the program. The basics of an interlock are:

If the RED light is on, the GREEN light can't turn on.
If the GREEN light is on, the RED light can't turn on.

You can actually program it that way as well.