plc novice in need of urgent advice!!!!!!!!!

hi all.
i have been working on a model railway set at college, its possible to control a full large scale system with tracks, signal lights, turntable, level crossing, loading and unloading truchs with a plc. i know this could be done with a brick or modular type plc but how?
what would be the advantages and disadvantages of each method?
looking forward to hearing your view on this.
cheers and take care

Okay, I fold. Whatcha got?...

beerchug

-Eric

i know this could be done with a brick or modular type plc but how?

Click to expand...

Answer: by lots of work and study, by being accurate and devoted.

Be accurate by nature, for example: don't let the capitals slip out of your posts. It looks very messy. If your programming is the same, God help you because in that case none of us can.

I'm feeling particularly mellow this morning, so I'll just make one helpful suggestion.

Brick and modular PLCs are not methods. They are packaging styles for the PLC hardware, and differ only in expandability, I/O capacity, and usually memory. They would both perform the same task using the same programming techniques.

The answer to your question is hidden in the above paragraph, but it will take the application of a little logic to deduce it.

just a guess ...

stephen,

I've got a hunch that you're asking about how to interface the train set's field devices to the PLC's I/O ... stuff like voltages, relays, position sensors, speed commands, etc. ... is this correct? ...

as to your specific question:

... brick or modular type plc ... what would be the advantages and disadvantages of each method?

Click to expand...

a lot of that answer depends on how many input points and how many output points you need ... and the types of signals (voltage levels, discrete type, analog type, etc.) that you're planning on hooking up to the controller ...

friendly suggestion: give us some more detail to work with and you'll get better answers ... the more detail you give, the better the answers will be ...

finally, what type of budget do you have to work with? ... and what is this "URGENT!!!!!" deadline that you mentioned? ... how soon do you need to get this "college level" model train set working anyway? ... note: "As Soon As Possible" is not a valid answer ...

Railway Question

hi all the above was a question i have been set, the instrumentation guys at work can not help me with it, so i hope some of your plc expertise can. i am still checking all available web sites for diagrams of brick model and modular plc design any ideas?

So this is a homework question, or a practical assignment.

Are you going to get this up and running or are you only working on the theoretical side?
If you are going to get it working, do they already have some PLCs sitting on the bench ready to go, or will you have to buy one in?

Generally a PLC is a PLC, so if it has enough IO, memory and speed, it can do the job.
If not, you should look for a different PLC.

Why don't you go to a PLC manufacturer's web site, down load some manuals and review what you got.
They will give you specifications, IO counts, capabilities and will even give you connection diagrams, voltages and current loads for the IO.

Some names to get you started:
Allan Bradley
Siemens
Modicon
Omron
Do a google search and you will be away.

Doug

Why would you even use a PLC on a model railway? There are better choices:

http://www.cwrr.com/nmra/Manb-Elec.html


John

Pesonally, I would use a TMR with RIO

Hard Wear-
Any relation to Codsack? (see this post )

Here is this TMR again...What is a TMR?

(assuming it's not short for timer )

I once got to go on a field trip to Safetran
They had a complete model railroad set upstairs with working lights signals and switches.
I remember that if power was lost, the gates had to fail closed.
It looked like a pretty neat place to work.