Newbie Questions

Hello all. I'm new to the world of PLCs and I have a few questions. I'm sure they have all been asked before, and I apologize for the repeat, but searching has not been bringing me the answers I'm looking for.

I'm building an animatronic figure, with 8 analog axes of motion (0-10VDC signals). Typically I would use a Gilderfluke animation control system, which works great for animation, but doesn't have any sort of safety interlock or manual override options. I need to keep the Gilderfluke system in place, but would need to add a system that can monitor the outputs, and also act as a safety/manual override system.

First, what sort of costs are usually associated with PLCs? After doing preliminary searches, I think something like an A-B Micrologix 1200R will meet my needs, but I'm not positive.

So if that were my PLC, what else would I need, and what sorts of prices would I be looking at? Obviously, the PLC, I/O modules, and some sort of operator interface. What else would need to be factored in? Are there any first time costs such as specialized software that need to be considered?

I know there will be a lot of man-hours associated with my programming/setup/learning curve as well. What would be a realistic timeline for learning this sort of system? While I am new to PLCs, I'm not a complete newbie when it comes to programming or electronics.

What are some vendors for PLCs and components? Whats the typical availability? What other options are out there that are roughly equivalent to the Micrologix?

Thanks in advance for your help.

You will probably need to use a safety PLC for this. Have a look at Pilz.

BobB said:

You will probably need to use a safety PLC for this. Have a look at Pilz.

Click to expand...

What is the difference between a safety PLC and any other type of PLC? Just to attempt to clarify, when I said I need saftey interlocks, I really just need some sort of programmable interlock. There wont be any people near this thing, and no real 'life safety' type issues.

I know no one likes to help out the new guy, but is there anyone out there who can give me some information? Even somewhere to look, or a place where I can talk to a real person about my system would be incredibly helpful.

Thanks.

Sam

Hi Sam, and welcome to the forum.

First things first.

You mentioned safety. How dangerous is this machine you wish to control? Give us a better idea what you are dealing with. Can it kill, amputate, break bones?

You should not use a normal PLC for a safety interlocking device for a machine capable of causing injury to people.

That is probably the main reason you haven't gotten many replies. Safety should not be done in a (normal) PLC.

Paul

OkiePC said:

Hi Sam, and welcome to the forum.

First things first.

You mentioned safety. How dangerous is this machine you wish to control? Give us a better idea what you are dealing with. Can it kill, amputate, break bones?

You should not use a normal PLC for a safety interlocking device for a machine capable of causing injury to people.

That is probably the main reason you haven't gotten many replies. Safety should not be done in a (normal) PLC.

Paul

Click to expand...

Thanks Paul.

As I said in my earlier reply, when I said safety, its not a life safety issue.

This is an animatronic figure. Its a hydraulically actuated crocodile. Its head moves, arms move, mouths opens and closes, eyes blink, tail wags. No one is ever going to be near this thing. I am looking for a way to monitor and override the animation system that I normally use. The system that I use does not have a way to easily limit movements if they can interfere with each other; for example if the head is rotated all the way to the left, and the jaw is open, then the arm can hit the bottom of the jaw. I need all the range in all the movements, so I cant put limits on the movements. I need a way to limit the movement only when the head and jaw are in a possible crash position.

I also need a way to operate this thing manually, when it isn't following the animation data. If the operators want to test a particular motion, I need a way to stop any animation data, and generate 'manual' inputs.

Again, there isn't really much risk of crushing, maiming, or killing anyone. Obviously 'Safety' was the wrong word to use.

As an alternative you could have a look at the Omron CP1L PLC and Omron CX-One software. The software package also includes software for screens, motion controllers, temperature controllers etc - it is a complete package.
A bit further up the line is the Omron CJ1 PLC. It is not a shoebox type but is rackless and plugs together on a piece of DIN rail.
Omron (and some other brands such as Red Lion) colour touch screens can also be used with either of these PLCs.
Yes, safety was probably a bad choice of words due to the safety PLC issue for factory automation etc.

sporkins said:

Typically I would use a Gilderfluke animation control system, which works great for animation, but doesn't have any sort of safety interlock or manual override options. I need to keep the Gilderfluke system in place, but would need to add a system that can monitor the outputs, and also act as a safety/manual override system.

Click to expand...

I think that the blurb about Safety scared most away from answering.
People are afraid of helping a newbie get himself into trouble.

If you go with an AB PLC you will need to purchase RSLogix software.
How many inputs and outputs will you be needing?
If it's not many, you can probably find a cheaper solution.
An Audio-Animatronic Crocodile sounds fun.
Keep the questions coming.

gbradley said:

I think that the blurb about Safety scared most away from answering.
People are afraid of helping a newbie get himself into trouble.

If you go with an AB PLC you will need to purchase RSLogix software.
How many inputs and outputs will you be needing?
If it's not many, you can probably find a cheaper solution.
An Audio-Animatronic Crocodile sounds fun.
Keep the questions coming.

Click to expand...

I've got 8 actuators, all responding to analog 0-10VDC signals. I want to monitor all of these signals, and then be able to output 'alternate' manual signals. So that means 8 analog inputs and 8 outputs. I'll also want maybe 4 digital I/O's.

Do those 0-10vdc command signals represent position commands or velocity commands, or something else?

If they are simply position commands, you should be able to do what you want with a PLC which provides enough inputs and outputs.

If they're velocity or servo valve commands, you might be disappointed with the ability of a PLC to control them smoothly.

Also, for monitoring the actual positions, what sort of feedback devices do those hydraulic cylinders have? Or are you just planning to use the command signals and assume that each actuator achieved its position.

Paul

OkiePC said:

Do those 0-10vdc command signals represent position commands or velocity commands, or something else?

If they are simply position commands, you should be able to do what you want with a PLC which provides enough inputs and outputs.

If they're velocity or servo valve commands, you might be disappointed with the ability of a PLC to control them smoothly.

Also, for monitoring the actual positions, what sort of feedback devices do those hydraulic cylinders have? Or are you just planning to use the command signals and assume that each actuator achieved its position.

Paul

Click to expand...

The animation controller that I use (Gilderfluke) generates a 0-10V analog position. That then connects to a PID feedback card, which generates a +-10V signal based on the feedback pots on the actuators. I was assuming that I could monitor this analog signal either before the PID loop, or after, and that monitoring before the loop would be simpler. Hopefully the PLC would not be effecting the signals during normal animation, it would just inhibit what I would call the 'crash conditions', where the arm can hit the jaw. The PLC would only be controlling the motions directly when the operator enters 'manual' mode, in which case smoothness isn't a huge issue.

How much does RSlogix cost? Allen Bradleys website is less than user friendly, especially when it comes to pricing of their products. I've found a few links to a free demo version of it, but nothing that tells what it would cost to purchase the full program.

sporkins said:

How much does RSlogix cost? Allen Bradleys website is less than user friendly, especially when it comes to pricing of their products. I've found a few links to a free demo version of it, but nothing that tells what it would cost to purchase the full program.

Click to expand...

See PicTure for prices and link for inline prices of other AB products. Also PDF for a compare of RSLogix500 packages.




http://shop.rockwellautomation.com/...BV_EngineID=ccceadeggeeggkhcflgcefkdffldfhi.0

sporkins said:

How much does RSlogix cost? Allen Bradleys website is less than user friendly, especially when it comes to pricing of their products. I've found a few links to a free demo version of it, but nothing that tells what it would cost to purchase the full program.

Click to expand...

See Picture for prices and link for inline prices of other AB products. Also PDF for a compare of RSLogix500 packages.




http://shop.rockwellautomation.com/...BV_EngineID=ccceadeggeeggkhcflgcefkdffldfhi.0

based on what you've posted so far, the $581 package will do what you want - as shown by my distinguished colleague Mickey ... the higher priced versions include "online" programming capability (making changes while it's controlling) - BUT - be advised that the Micro-1500 that you've mentioned doesn't support "online" programming anyway ... so in that respect, any extra money for the software will likely be wasted ...