Hi guys,

I am trying to build a project which is a blend of both PLC and microcontroller (Arduino perhaps ). The project is something like a punctuality system for schools and college which will lock the students out of the class if they are late.

The logic of the system is as such:
1. The green light in ON at all times whenever the class is unoccupied.
2. For example, the time is set at 8 a.m. Electromagnetic lock and red light are ON at 8 to indicate the classroom is having class.
3. Before 8, students are able to enter the classroom by thumbprint (wrongly written as fingerprint). After thumbprint is verified, students are allowed to enter.
3. The buzzer is ON if someone is trying to hold the door. For example, I am late and my friend trying to hold the door open for me. Let's say the ladder diagram is set to turn ON the buzz after door is not closed in 30 seconds.
4. Exit button is for students to go out from internal access.

The conditions to enter the class:
Thumbprint of students must be individually programmed into Arduino, then verified and must not be late.

I am trying to say like, let's say I build a microcontroller alarm clock (refer to attachment) and feed the alarm output (buzzer) into the PLC input or when a person's thumbprint is verified (thumbprint sensor will be programmed and connected to Arduino), the electromagnetic lock connected to the PLC will disengage. How to integrate both systems?

The PLC I plan to use is Mitsubishi MELSEC A series. I already have A1S61PN and A1SY10 on hand.

 

It seems most of the functions are performed in the Micro?
If so, why not just use that as the Mits does not seem to be doing all that much.
The interface from micro to PLC is should be rather simple, opto etc.
Max.
.

 

Hi Max,

The focus of this project is not the project (yes, you read this right ), but to learn how to integrate both systems as I have not done it before, therefore curious about the possibility.

The interface from micro to PLC is should be rather simple, opto etc.
.

Will you explain how the interfacing can be done?



Cheers.

 

Mits inputs can typically be set for sink or source input, again, typically 24vdc.
One simple way is to use a opto isolator, anything from the simple 4n25 etc.
For PLC input it is quite sufficient.
B1 = PLC input.