Some guidance with PLC for a newbie

Thread Starter

MrR0b0t0

Joined Feb 5, 2021
4
Hi everybody.

I have recently decided to take up PLC programming as a hobby to familiarise myself with it with a view to doing a course further down the line. I downloaded the Crouzet Millenium 3 software as it is free and apparently so easy to use. But guess what? I am still confused haha.

Anyways I am just playing around with a small little circuit using the function block programming where i want to run a little lamp for a certain amount of time after a start button is pressed and 4 sensors are giving an input to the PLC, the 4 sensors are pretend safeties to say that the door is closed and my little oven can make my muffin.

I have the timing part right where the lamp goes on and back off after the timer goes on and off. However if I open one of the sensors in the simulation and close it again the timer stops and then starts back up by itself and i am just not sure how to put a manual reset in so this doesnt happen. I have attached a little snip of what i am doing and hopefully its clear as i may be way off or not.

Inputs 1- 3 are my pretend sensors and input 4 is my stop
Input 5 is my start and input 6 is the timer reset
 

Attachments

MaxHeadRoom

Joined Jul 18, 2013
23,100
IMO you may find it easier to program in ladder format, it also makes it easier when monitoring/trouble-shooting as the status of the boolean function is visibly shown.
Some PLC's do not have the block function programming active.
Max.
 

Thread Starter

MrR0b0t0

Joined Feb 5, 2021
4
IMO you may find it easier to program in ladder format, it also makes it easier when monitoring/trouble-shooting as the status of the boolean function is visibly shown.
Some PLC's do not have the block function programming active.
Max.
Hi Max

I have been tinkering around with the ladder logic for the Crouzet software and have included a snip of what I am doing. Again in the same way as Iwas with the FBD I want a certain amount of conditions to be met before I can start. So in the case of the first line I want all of the safeties to be engaged so I can set M1 which I am calling a flag to say yes its ok all safeties are in place. However when I try this in the software i get the message as you can see in the first image telling me that the M1 is incorrect.




However when I looked into the examples of using M1 for these type of things in the actual Crouzet manual I came across this example in the second image where they are using M1 in the coil section and then further down the ladder to control the lamps. But when I do it I get error messages or simply cannot put the M instructions into the contact sides. Am I doing something silly or just missing something simple?
 

Attachments

MaxHeadRoom

Joined Jul 18, 2013
23,100
Strange! I am not familiar with the Crouzet PLC, but using an output as a contact expression in any rung is usually a valid command in ones I use?
Not sure why it would error?
Is there any support forum for Crouzet PLC?
Max.
 

Thread Starter

MrR0b0t0

Joined Feb 5, 2021
4
Hi Max
Yeah I contacted Crouzet themselves but with the way things are it could be a while before I get a reply. In the meantime my friend who works in the Industry is giving me a student copy of the Mitsubishi GX software as he said he uses them most out in the field and finds them the best to work with in his opinion due to their user friendly interface. Like yourself too, he hasn't really worked with Crouzet but agreed with what you said in your last comment about flags and rungs being standard in most software programs.
 

strantor

Joined Oct 3, 2010
5,543
I'm not familiar with crouzet either, but this turns me off to ever giving it a try.

I think the error text suffered some losses in translation. I think what it's trying to tell you is "hey, you programmed in an "auxiliary relay" (memory bit) (M1) and then didn't use it anywhere in the program. M1 is not an output and Your program isn't going to do anything."

Try adding a rung below that one, with a normally open contact M1, going to output coil 01


EDIT: just re-read where you said you already gave that a try. I don't know what else to suggest. I noticed in the crouzet example you posted there is some inconsistency with the case (M1 vs m1). Maybe they have some strange rules about case? Have you tried using lower case? It's a stretch but I got nothing else.
 
Last edited:

Thread Starter

MrR0b0t0

Joined Feb 5, 2021
4
I'm not familiar with crouzet either, but this turns me off to ever giving it a try.

I think the error text suffered some losses in translation. I think what it's trying to tell you is "hey, you programmed in an "auxiliary relay" (memory bit) (M1) and then didn't use it anywhere in the program. M1 is not an output and Your program isn't going to do anything."

Try adding a rung below that one, with a normally open contact M1, going to output coil 01


EDIT: just re-read where you said you already gave that a try. I don't know what else to suggest. I noticed in the crouzet example you posted there is some inconsistency with the case (M1 vs m1). Maybe they have some strange rules about case? Have you tried using lower case? It's a stretch but I got nothing else.
Yeah I gave that a try as I said before I was wondering if I was doing something silly like caps lock or incorrect punctuation but still got the same errors. I have downloaded the GX stuff within the last hour or so and it seems to be a lot simpler so far and a lot clearer. Apart from youtube would anyone have any good learning websites to recommend for learning the Mitsubishi?
 

MaxHeadRoom

Joined Jul 18, 2013
23,100
Hi Max
Yeah I contacted Crouzet themselves but with the way things are it could be a while before I get a reply. In the meantime my friend who works in the Industry is giving me a student copy of the Mitsubishi GX software
Yes, I mainly use Mitsubishi and am more familiar with it.
Max.
 

pitzMike

Joined Apr 5, 2021
1
A bit late but based on the snippet of the manual you've shown, you should probably use the Output Bit O1 instead of the M bit. Havent used Crouzet either.
 
Top