Looking for advice on making an Auto-Start feature on AB Micrologix system

[BrokenHorn]

Hello All, I'm new to this forum, but it looks like a great resource and I've already got some ideas for changes to my system from the information that you've shared.

Earlier this year I built a HERMS system similar to Kal's electric brewery design, but using an Allen Bradley MicroLogix PLC and Red Lion G3 series 15" color touch screen. I've attached some pictures.

My question for this post is, based on this system hardware, what would be the best way to program in an auto start feature that would allow the system to kick on in the morning to start warming the HLT (so I can sleep longer)? The HMI has a real time clock (I've read the Micro 1100 does too but not sure) so would it be better to program this in the HMI since its just triggering the HLT warming process based on time and temperature presets and turning on a the recirc pump? Or are there reasons that this needs to be in the PLC for future automation additions? If I knew that the PLC has a real time clock and how to reference/utilize it then I would probably just program it there and continue to use the HMI just for interface. Maybe thats the answer to my question, but then it raises other questions (like how?). Currently, valves are still manual so I'd have to fill with water and prime the pump the night before, but eventually I will add actuated valves, level sensors, etc to be able to incorporate more automation.

Thanks for any input and let me know if you need more information. I have seen other posts about people setting up an auto start function but they were using different hardware. If anyone knows of another post or resource for a similar setup please guide me and we can avoid rehashing too much of it here.

Lastly, if you see any issues or concerns with the wiring in the panel, let me know. I don't claim to be an electrical expert and know just enough to create headaches for myself.

 

[trimixdiver1]

You could do a countdown timer, I'm a AD guy now, but there may be a compare function.

 

[evanmars]

This will turn on bit B3:0/0 at 6:45 am assuming you have the RTC set to the correct time.

 

[BrokenHorn]

Thanks Evanmars, I actually got it worked out last night and am going to test tonight. I tried putting that functionality in the HMI but I don't know enough about C programming to be comfortable with it. What I ended up with is similar to what you showed but I am comparing the RTC:0.HR and MIN to integer addresses so I can write to them from the HMI and adjust the start time.

Now I just have to configure the HMI to email/text me when it's all up to temp and ready to go... That's not too lazy is it? 😄