My first PLC project finished!

backendcode · Oct 12, 2017

Hello Everyone,
Finally, I have finished my first PLC project! I made a little video of how my conveyor system works! Please follow the link below!

https://youtu.be/9L4EN_SmP7o

My company makes the metal door as you can see in the video but I just used a piece of metal of test the conveyor.

Thanks everyone for help and support! There are many usernames I remember on this forum who constantly reply my questions and I can't name them all but thanks everyone.

A video might not explain it very well but please don't forget to give your feedback or any advice!

Best,

Handcraftedsince87 · Oct 12, 2017

Well done! One of my favorite parts of what we do is stepping back after all of the hard work, and watching your machine come to life.

backendcode · Oct 12, 2017

Handcraftedsince87 said:
Well done! One of my favorite parts of what we do is stepping back after all of the hard work, and watching your machine come to life.

Thank you! I had the same feeling! After finishing this project I was feeling so relaxed and I am like let's make a video and share with people in the same industry! I get so much help from this forum on this project!

Thank you again,

janner_10 · Oct 13, 2017

Looks like a loose connection on that conveyor, it keeps stopping.

PS Well Done!

backendcode · Oct 13, 2017

janner_10 said:
Looks like a loose connection on that conveyor, it keeps stopping.

PS Well Done!

Thank you for the response janner_10,

Actually, I put 3 seconds delay at every prox to avoid the situation where somebody comes and lifts up a part(door) for a second, It stops because of debouncing time.

Thanks again,

gclshortt · Oct 13, 2017

Looks good.
If one of the proximity sensors malfunction, do you have a way to indicate this and stop the feeding of material?

Regards,

LoganB · Oct 13, 2017

Great work dude! It's definitely the best feeling to see your work finally controlling a process and doing it correctly. Here's to many more success stories

jstolaruk · Oct 13, 2017

gclshortt said:
Looks good.
If one of the proximity sensors malfunction, do you have a way to indicate this and stop the feeding of material?

Regards,

+1

Handling faults or device failure is a big part of programming.

Excellent job so far!

LoganB · Oct 13, 2017

gclshortt said:
Looks good.
If one of the proximity sensors malfunction, do you have a way to indicate this and stop the feeding of material?

Regards,

Based on the following understanding of the machine's first two conveyors:

1. Machine power up, all sensors are false for sensing part (0).
2. Part placed on conveyor covering prox 1, changing prox 1 state to 1.
3. Four seconds later motor 1 (&2?) starts.
4. Prox 1 will switch back to zero as part moves ahead.
5. Motor 1 (&2?) will run until prox 2 is covered and then halt.

Fault logic usually goes on its own subroutine. To monitor the proxes and make sure they are working, I would do the following:

Have a rung with an XIC examining Prox 1, followed by an XIC examining motor 1 (in series).

If both are in a state of 1, start a TON with a preset of 3 seconds. If that timer finishes, you know that your motor has been running but a part seems to still be covering the prox. This can be flagged as a "conveyor 1 motion fault". Use the timer.DN bit to set an alarm flag, which should drop your conveyor out of auto mode and alert nearby operators either with a buzzer or a flashing red light. This will cover both a stuck part and a bad prox that's stuck on. Use combinations of timers and prox state changes to monitor each prox.

(Not sure if you needed any guidance in this regard or not, but I figured I would give an example just in case

)

backendcode · Oct 13, 2017

gclshortt said:
Looks good.
If one of the proximity sensors malfunction, do you have a way to indicate this and stop the feeding of material?

Regards,

I haven't written a code to detect sensor fault yet! Can't think of logic :/

But I have written contactor fault and motor overload fault and conveyor system will stop and turn on motor fault indicator light!

Any idea about the logic? how can I find sensor fault? I was thinking to use timer

For example, conveyor 1 will only turn ON, if there is part present on conveyor 1 and no part present on conveyor 2, and if the condition becomes true! motor 1 (conveyor 1) should turn on and within 2 or 3 seconds, my part will start moving and sensor should be 0 now at conveyor 1 and if within 5 seconds sensor doesn't become 0 which means that prox is stuck at 1 or vice versa!

Please give me advice on that!

Thank you,

backendcode · Oct 13, 2017

LoganB said:
Great work dude! It's definitely the best feeling to see your work finally controlling a process and doing it correctly. Here's to many more success stories

LoganB, Yay!! did it man! Thank you for your support! I remember your quick response to my thread! I really appreciate you for that!

Respect!

Thank you again,

backendcode · Oct 13, 2017

LoganB said:
Based on the following understanding of the machine's first two conveyors:

1. Machine power-up, all sensors are false for sensing part (0).
2. Part placed on conveyor covering prox 1, changing prox 1 state to 1.
3. Four seconds later motor 1 (&2?) starts.
4. Prox 1 will switch back to zero as part moves ahead.
5. Motor 1 (&2?) will run until prox 2 is covered and then halt.

Fault logic usually goes on its own subroutine. To monitor the proxes and make sure they are working, I would do the following:

Have a rung with an XIC examining Prox 1, followed by an XIC examining motor 1 (in series).

If both are in a state of 1, start a TON with a preset of 3 seconds. If that timer finishes, you know that your motor has been running but a part seems to still be covering the prox. This can be flagged as a "conveyor 1 motion fault". Use the timer.DN bit to set an alarm flag, which should drop your conveyor out of auto mode and alert nearby operators either with a buzzer or a flashing red light. This will cover both a stuck part and a bad prox that's stuck on. Use combinations of timers and prox state changes to monitor each prox.

(Not sure if you needed any guidance in this regard or not, but I figured I would give an example just in case )

LoganB, Your understanding of the machine operation is 100% correct. Holy!! how did you know I put 4 seconds timer when the part is placed on prox 1 lol.

Prox fault! Thank you for explaining the prox fault! I haven't written a code yet for prox fault. But I think your advice and example is the best and I think I can do it and I have sensor fault indicator light on the control panel, I will turn that light ON if the .DN bit of timer will set and drop the auto mode of the conveyor system.

Thank you again,

LoganB · Oct 13, 2017

backendcode said:
LoganB, Your understanding of the machine operation is 100% correct. Holy!! how did you know I put 4 seconds timer when the part is placed on prox 1 lol.

I've looked through your code a few times to give advice, so I remembered seeing the delay timer

Another trick a lot of us use is to place a timer in your fault logic routine on a rung with NOTHING but an XIO for that same timer's DN bit to the left of it. This setup creates a timer loop so that it will continue to count up, reset, and count up again whenever the machine is in run mode. Set the timer's PRE to 1000ms (1 second).

Then, in your fault logic where you are turning on the fault light on your control panel, please a LEQ (compare) to the left of the OTE that activates the light and tell it to compare the TON's .ACC value to 500. This means while your timer is running and your machine is in a fault state, the OTE to activate the light will be ON for half a second, then OFF for half a second. A blinking light is much more likely to catch someone's attention than a solid one.

You can adjust the TON's PRE and the compare value to change the rate that the light blinks. A PRE of 2000 (2 seconds) and your LEQ using 1000 will make a light that is on for 1 second, and off for 1 second.

nmurray · Oct 13, 2017

Nice Job!!

Its always nice to see project work.

As far as Photo Eye failure, you know a part is coming to that conveyor, so I would use a timer and wait for x seconds and if no part is seen then alarm. This would also cover if someone picked up the part...

Just make an indexer to track parts then if one goes missing alarm out and require someone to acknowledge it.. If you go this route you can also count how many parts are made each shift and start tracking downtime... Bosses love that ****.

Mispeld · Oct 13, 2017

Something to consider is additional emergency stop push buttons along the conveyor. I see one on the main panel, but consider the following scenario: someone lifts a door at one of the center sections, and does so in a way that the proximity switch loses detection. The person exceeds the allowable time delay, and it triggers the start sensors to index a door into that section. Now the person drops the door, but is it too late to stop a "train wreck?"

This is where e-stop button(s) along the conveyor frame can allow for a rapid shutdown. Otherwise the person must run over to the main panel to e-stop.

The challenge is locating the e-stops such that they are not accidentally bumped, yet still easily accessible in an emergency. I would be looking for places under the rollers, near the conveyor legs, and recessed to avoid inadvertent hits.

My first PLC project finished!

backendcode

Member

Handcraftedsince87

Lifetime Supporting Member

backendcode

Member

janner_10

Lifetime Supporting Member

backendcode

Member

gclshortt

Member

LoganB

Lifetime Supporting Member

jstolaruk

Lifetime Supporting Member

LoganB

Lifetime Supporting Member

backendcode

Member

backendcode

Member

backendcode

Member

LoganB

Lifetime Supporting Member

nmurray

Member

Mispeld

Member

Similar Topics