Hello,

I am relatively new to PLC's. I did a course way back when i was an apprentice but dropped out after a few lessons due to finishing a 6 week project in a day and told to sit quietly for the the rest of the time...

For the past 5 years i have been working as a lead engineer in the HVAC controls field and am looking at re-learning PLC's as the hardware can be alot cheaper for certain applications (ie dumb I/O like switchboard monitoring) and i get the request a fair bit.

I have been playing with some of the automation direct software and the rockwell rslogix micro lite software with the emulator with success and now want to move on to getting some hardware for a more real world playaround.

My question is what PLC, HMI and required software would you recommend purchasing? (im not worried about brand at this stage)

I understand the price of the automation direct CLICK series is suggested alot although i dont know if this fits the bill for a test controller that im after. I also dont understand what it means by 21 instruction whether that is 21 instruction types or 21 instructions in total .

It would be nice to be able to do
- PID control (or write my own).
- Analogue control.
- Capability for high speed counting.
- Mid range control to perhaps do a large chiller manager routine (as a test study)
- Modbus master/slave over IP and rs485
- Optional C++ integration would be nice but i hear that is rare and is more VB these days


What may some of you suggest for a test product based on the above? (PLC, HMI and required software)

Thanks in advance

I would suggest the CLick as a sound choice for learning. Get an "analog" unit. It will do thousands of rungs not "21". That's 21 instruction "types". You would have to write your own PIDs. Google "Click PID" and you will land on a spectacular website that is a free training site that has many lessons using three common PLCs in each example and the Clicks are one of them. They have a PID for Click.

Keith Cress
kcress - http://www.flaminsystems.com

Bah I thought I had put in a reply to this thread before I was away, sorry about that but yes I agree with itsmoked. It is a simply PLC compared to some that are out there but worked great as a learning tool and for the projects I have had to do thus far. He is correct about the thousands of rungs comment and only 21 instructions (NO, NC, Math, Set, Reset, etc...)

sorry for the delay in a reply but glad itsmoked got to it with the same advice!

Thanks for your replies.
I had actually forgotten i wrote this post waiting for a comment although i did end up getting an analogue Click controller so its good to see that is still the general consensus.

Ive actually connected it via modbus to a BMS controller which mimics the real world IO reactions in conjunction with some easyveep project examples which is a fun learning process.

ps thanks for the PID reference. I hadnt thought of creating one yet and that is a good start to see how the click interrupt is set up.

Great!

What's that BMS controller? Do tell.

Keith Cress
kcress - http://www.flaminsystems.com

Building Management System Keith, it's an HVAC term.

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Ah. Thanks Jeff.

Keith Cress
kcress - http://www.flaminsystems.com