interfacing PLC to equipment

Howdy folks
I am a design engineer working for a rather small company in the middle of heartbreak silicon valley. I was hoping to find a book or a standards manual on interfacing PLC to equipment.
In my former life I use to design wafers, cpu systems, I/O devices and unfortunately I also became a programmer ( oh man my methodone just ran out). All in all I always had some standard by which manufaturers agreed upon as a common pinout/cable wiring etc... convention.

I have to interface a 80 KW UV drying system to a newspaper printing press. Two inputs from customer PLC and I supply 9 outputs (buffered) for thier measurement.

Any suggestions....

well I guess that there are no industries standards...though one would think there should be..after all it doesn't matter whose hard drive you buy...it still works, it rom-bios still interfaces with the the system bios
so my thinking is if a customer has a PLC, PLC software, and an interface then that customer should be abale to change any one of the componets out and thier system still works..

I hope I haven't bored anyone to death..
ta ta for now

lonnietillett

well I guess that there are no industries standards...though one would think there should be..after all it doesn't matter whose hard drive you buy...it still works, it rom-bios still interfaces with the the system bios

Click to expand...

So the all the chips in a mac will work in a pc?

What kind of standards are you looking for exactly?

Something like: Use this type of eye for this and this type for that?
A 3 pole relay for this and a 2 pole for that?

Every brand has their own "standards" as far as the actual plc goes.
The machine is a matter of need and space.

If you can shed more light on exactly what those inputs and outputs do just about anyone on here can steer you in the right direction to the available products to get the job done professionally.


One other thing, It seems like you have already blown off this site as a source of info but if you didn't keep in mind everyone on here is posting answers on there own time and free will. No one on here gets paid to respond to anything. So you must give time to get responses. One hour at 10 pm is just not going to get what you desire!!!

The standards manual is EE-101 and the NEC. connecting to a PLC isn't like an circuit board tying to the pins on a chip. These are power control devices, and the connection follows rules closer to those used for wiring your house than those used for designing an ASIC!

Get up from your desk, go out to the factory, and take a look at similar machinery. Get drawings from a similar project, and talk to an experienced maintenance man or plant electrician. Don't worry about embarassing yourself, and ask a lot of questions. Apply fundamental electrical principals to everything you learn. And for goodness sake, if you are in over your head ask for help from someone on site! Nobody gets killed letting the smoke out of a PC, but you can kill someone with this stuff!

Thankyou for the input I will look up those standards if I can.
We here at UVEXS do not process anything...

I design these big huge machines and believe me I know of the need for safety and proper design of this hardware...we do not use any PLC here...but our customer's do and that is what I was hoping to find .... an interconnection or standards which would tell me a simple scheme or convention used for transmitted values and this port, receive values on that port.

The mechanical and electrical stuff I use in my design are kind of extreme and NEMA-4 category, heck the power supply just to light one lamp is about 800 pounds..480 volts, single phase, 70 amps ... just to produce 1400VAC at 15.4 amps for each lamp...for a total of 4 lamps...

from what I can tell in previous projects that other engineers before me here design ... it appears to be ( well to me anyway) random selection...use any pin or port

Do you need to send data to them or are we talking just telling when to be ON/OFF?

If its data then you need to found out what plc they are using...I have a UV system on a press that uses an AB SLC 500 with panelview for setup ..ie lamp settings, using 1 or 2 or 1 and 2.

You need to be more specific about what is being used...ARE you using a PC and need to send/collect data with their PLC? Depends on the PLC how you interface, some can be done with RS232, others need special adapters.

FYI the system you refer to is standard. I have UV drying systems being used on printing press 3PH 480v 60hz 93kva 112 Line amps.

I do not know what PLC device they have.

I use the pic controller to handle all the startup, warmup, heater and vent controls via front panel controls ( set it and forget it type of thing )

I do allow the customer to use remote turn on/off (via 24vac 300ma relay control) and I send back percentage of power used (min=30%,max 100%) and thermal air temp from the ducting as well as shutter open/closed, lamp out error, lamp ready signals ... all output signals are opto-isolated..all signals digitally under pic control..and my various internal process I developed for this machine to ensure safe an proper control for the life of this machine ( about twenty years I hope)...hence these are nothing more than indicator lights for them to monitor...and stop their web if needed.

Eventually I'll give them remote power usage but they seem to be happy with only front panel power usage controls, this is for an 80 inch web design.

As of now I guess I'll start my own standard as to chan#, I/o port structure and create an inhouse table for those engineers that follow me here.

I had hope that an industry standard was available ... but after reading more about PLC and vendors of PLC equipment it seems a mute point as it appears that whoever writes the code controls the I/O space.

It does mean I'll have to revise my pic codes to allow for unamed channels..more programming but not as bad as one might think. I'll use a ground pin approach ( ie chan one active because a ground has been detected)

I do thankyou for your help...