PLC Selection

Hi Kapil here....
We got a project in which we have to write code for an electronic hammer machine, which will control the mechanical parts of the machine...
Machine actually convert silver bricks into foils...i want to know which PLC will be better to use and why....
regards

Oh Boy,

::hides the can opener::

Seriously, though, without a little more info, all you are going to get is brand preference, but nothing you can use.

How big is this hammering machine? How much IO? Is it intended for a plant network? What kind of operator interface do you have in mind?

For small projects, or larger projects suited to a distributed control scheme, I recommend Unitronics. They have a range of units, expansion IO and networking capability. I'm not sure if they're doing ethernet yet, but I'd heard they were looking into it.

For servo-intensive projects without alot of IO, check out Trio. They have many sizes of motion controller available, that can interface to just about any servo drive you like. The programming is in a BASIC derivative, like alot of other motor controllers on the market.

Lastly, for large scale jobs, I favor the Giddings and Lewis lines. MMC units program in ladder logic, with all the servo functions built right in.

Good luck!

TM

Hi Thx for your reply and now can i answer all your questions....
Machine is around 15 feet long and it has got two hammers at two sides (lenght wise) there is a center circle in betwwen the machine where we load the material to be hammered....
it has got 16 holes where we put material and those 16 holes revolves around in a circle......
now when left hammer is hammering one packet or one bundle of materail , the other hammer is also doing the same work with same speed and same intensity....
now we can name all the 16 holes as A1,B2,A3,B4,A5,B6 etc...
when left hammer is on A1 , right hammer is on B2 and so on.....
now 5 cycles have to be completed on every packet....every cycle consists of 4 type of programs or 4 different types of (sppeda nd intensity) of hammer....
i hope you got my point here....
one complete cycle takes around 1hr 35 min to complete one cycle....

The control panel which they are looking for must contain ....
4 different types of options where they can set speed and intensity , which will decide final thickness of the material....

just start and stop button...
nothin else they want....
yes this machine is going to be used for a plant...but i don't think so that they require any networking capabilities....

you suggested few options in your last post and i think i gave you little more explanation....
now how should we proceed...which controller we should use and is there any option through which we can choose which type of memory will be suit us....

regarding IO, They don't require anything special except mechanical parts workins, but they do require display for selecting different options as i told you for

every packet has to under go 5 cycles and every cycle consists of 4 options like
lets say option 1 - speed 10 intensity 20
option 2 - speed 15 intensity 18 etc...

so....what do you think .....

What method is going to be used to drive the hammers? Since you must control both speed and force, independently (is that possible? Terry, Ron, jump in anywhere!) it makes me think motor-driven, but perhaps I'm wrong. Also, what will drive the table?

On the surface, it sounds like a fine job for a Unitronics M90, or perhaps one of the upper models. They have a built-in operator interface and keyboard for entering parameters, plenty of I/O on board (expansions if you need them).

The M90 also has some nice features for interfacing with external equipment. You can use the common IO route, or use the Protocol function in the software to set up RS232 communications with, say, a servo drive.

Finally, they program easily, and are cheap-cheap-cheap. Best bang for the buck on the market, but that's my opinion.

Good Luck!

TM

I agree with Tim to the extent that a PLC with a built-in display would (should) work well. That would relieve you of a lot of extra effort (extra software, hardware and programming). You would still have to do some programming for the display, but it should be relatively easy since it is part of the controller.

As far as which brand of PLC to use... look around in your area for local reps that are supported by the manufacturer. Only you and programmers in your area can answer that question.

It sounds like you might need to have a PLC that is capable of delivering analog outputs... 4-20 mA, 0-10 VDC,... for the purpose of controlling the speed and intensity (?Force?).

The application sounds very simple!

Automation Direct has plenty of PLC's that are more than adequate! However, I don't know if they have any with built-in displays... (Tom?)

I'm curious... What is the "hammer" and how does it work?

As far as controlling speed and "intensity" at the same time... it depends on what the "hammer" is and how it operates.

About Position/ Pressure Control.

TimothyMoulder said:

What method is going to be used to drive the hammers? Since you must control both speed and force, independently (is that possible? Terry, Ron, jump in anywhere!)

Click to expand...

One can control position or pressure or limit both at the same time. One cannot control position and pressure at the same time. Hammering?
Normally the metal is just rolled back and forth between two rolls that get closer each time. When the metal is thin enough it is rolled through a few precision stand ( rolls ) to reach the desired thinkness. This can require fine motion control if there is more than one set of finishing rolls.

Terry,
I have used hammer who is as magnetic solenoid with return spring.
Force come with current and frequency by digital output control 'hit'.

seppoalanen,

There's at least a million ways to hammer something. Heck, you could even use that broken, old PLC as a hammer!

It would be kinda useless to guess what kind of "hammer" Kapil has on site. I'm gonna wait to hear what he has.

Peter,

Kapil specified "speed" and "intensity". I assume he means "force" when he says intensity. As far as "speed" goes, I think he really means "strokes per ???".

As seppoalanen mentioned, a coil-driven, spring-return, hammer could operate by "trigger". The "speed" controlled by the "trigger-rate".

Again... Since there are some pretty weird things out there in the world, I'll wait to hear what he has.

Ths for all the nice replies...well i got your point and have something in my mind...i will try and read some manuals and try to figure out the best possible thing for me...
Well, if i talk about hammer it is mechanical but have got inputs which i have to feed through plc...
regading postioning , we don't have to position the material simultaneously but but yes he have to beat it with particular intensity and speed...and i don't kow why coupls of replies said that it's not possible, i wish if i am not wrong or not mis understanding you guys well i will try and respond after reading some material...

regards

Just curious

How is this process done now?

Is any PLC involved in the existing (if there is one) process now?

What are the number of digital inputs and outputs needed?

What analog inputs and outputs may be needed?

Is any motion or temperature control involved..ie PID?

What brand PLC's are strongly sold and supported in your region?

For many of us a choice is made by others. For many the choice is made by area. For many the choice is by choice.

The answer to ALL the above questions may offer some good advice on a choice that may fit your needs...OR...a choice you are deemed to accept.

Kapil,

Please describe the hammer and how it is driven.

This isn't a "gravity-hammer" is it?

hi all
hmmmm. i am going to client's place with in this week and i will collect all the information which you people have asked for...
I will try to get as much information as possible...
regards

The AutomationDirect DL-06 does have a built in display, and is very reasonably priced. I haven't used it myself, though, as I have foind that graphic displays provide better insight into machine performance and are generally easier to proggram than text only displays for changing setpoints and displaying a lot of data.

If this is your first project, AutomationDirect.com may not be your best bet - you may need to have access to a local distributor for component selection and tech support. If you have done a project r two, though, I definitely recommend their products.