I am looking for a very simple. 8 bit PLC

[rsdoran]

Lets see if I have the gist of this. You have a system involving a linear actuator that could be driven by servo or stepper motors. You want to develop a "DEMO" system that a SALESMAN could use for demonstration.

Now lets talk shop. WHAT stepper or servo system WILL be used, is this something your company makes? IF so then what type of "COMMAND" will it need to make the motors run? Digital? PWM? ??? If an off the shelf system will be used please tell us what brand/model.

The finite details have not been established. Does the device have 13 inputs and 5 outputs or does the PLC need 13 (digital) inputs and 5 (digital) outputs?

Will the device be pure digital OR will you need SERIAL (I like Cheerios) interface?

If storing "position tables" on the PLC how will the servo/stepper system get the info FROM the PLC?

Many have suggested micro plcs BUT noone really knows what you WANT to do so its hard to offer a DEFINITIVE answer. Please offer more details on the project.

 

[elevmike]

Still sounds like a job for the Automation Direct DL06 with an counter option module.

 

[uhu_fritzl65]

Hello Terry,

the actuators are in position when an encoder reads the desired position. I can define anywhere along its stroke.
The inputs and outputs I mentioned are the ones on the servo amp that I have and it is junk...I would like t hear how someone else would do this...I am trying to answer your questions Terry I am just uncertain as to how.

What exactly drives the actuator to move to one particular place or another?
A rotary type of motor. Could be servo could be stepper.

It sounds like you have a "driver"... somewhere, that can "call" upto 32 different numeric values... from "somewhere". Where does that "driver" reside?

I currently have a driver but it is very unstable with the motors I have..


It sounds like the PLC might be an "after thought"... a simple repository for holding data... how do you plan to load that data into the PLC? How do you plan to extract that data from the PLC?

I am currently connecting to this driver via a com port from a laptop

 

[Unregistered]

Hai Mr,
I am sorry i donot know the name of the person with the question .
but i have a solution thinking the system as follows
u have a linear actuator with the motors and drives
but u need to control them using the PLC
ok use a small PLc a microPLc like ABB AC010 PLC or Siemens Logo
and interface all ur start buttons of all the axis and the outputs of the plc to the start input of the Drive
then u can write ur logic required
i will try to send u a connection diagram
but the speed of the motors should be set in the drive itself and the only way to control the position of the motor is either through the stop switch
or using a timer or using a counter (step count)

ratna kanth
ABB

 

[Peter Nachtwey]

I think this close to what uhu_fritzl65 wants to make

This is what we make for our salesmen ( our salesmen are well trained so I would never call them names ) and distributors ( I do have a phrase to describe distributors ). This are BIG .jpgs

ftp://ftp.deltacompsys.com/public/jpg/P4270020.JPG
ftp://ftp.deltacompsys.com/public/jpg/P4270024.JPG
ftp://ftp.deltacompsys.com/public/jpg/P4270025.JPG

However, there is no 8 bit plc because the motion controllers can do its own sequencing. The little controller on the right can do 60 million float point operations per second. Now what would the 8 bit PLC do? The whatever work the 8 bit PLC could off load the DSP would be offset by the time the motion controller would spend communicating to the PLC.

The trick is in the packaging so these demos are small, light and very rugged so the airplane monkeys can hurt it. It is the pits to get in front of the customer to do a demo and find your equipment doesn't work. Our new versions will have a small HMI in the lower left hand corner.

 

[Terry Woods]

uhu_fritzl65, take a gander at this...

http://www.cnc-hobby.com/stepper-motor-driver-design.html

You can buy a complete system... or you can take the time to learn how to build your own.

 

[Colossalnut]

Confusion. Sold!

I may appear a little rude here, but have you or your company ever developed, sold, or even experienced linear actuators in the past? If so, what is your most common application? How have you successfully controlled them in the past? I understand that you're new to this and you say you haven't programmed PLC's for sometime, but I doubt that you'll get step-by-step instruction here. An enormous amount of information and alot of extremely helpful hints, but not a classroom. Check-out the material available here. I'm sure you have as much of a desire to learn as the rest of us! However you must first read, study, apply, learn, repeat! Ask informed questions along the way (not before you ever start).

 

[uhu_fritzl65]

Good Day All,
first off thank you all for your replies and suggestions. colossalnut, the company I work for is a global leader inthe linear motion guide business and we enjoy a good reputation. I dont think it was a rude post and I wouldnt worry about it. I ask only to inform myself and get smarter in this realm. This all started out because before I came on board a product manager took 2 actuators and 1 servo amp to a dmocase builder. No schematics or drawing whatsoever. The tech who suvbsequently wired the demo case used 2 relay to switch the encoders and power lines from one actuator to another, whilst the amp was powered up. Smoking the actuator motors nicely. I have given some consideration to using some time delay relays to ensure that the amp gets powered down before the switching is done, but I think that this is not going to be the solution. So I asked here about a plc...
I am going to mount 2 amps in the case and be done with it. One for each actuator. I think that this is way will be safest and moost robust for all involved. I am impressed with the demo cases Pete has shown and when the next product release comes up, I will follow along his lines.

Most of all I would like to say that my experience here is a good one and I look forward to the day when I can be of help to someone.

thank you all for your time and efforts

fritz