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PLC simulator ideas

windsormw

Aluminum
Joined
Dec 11, 2006
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The corner of Hill & William
gentlemen ......

Id like to be clear . I'm a millwright with zero programing experience , relay logic skills are effective but not superior . Industrial control has always fascinated me , megabits to mosquito bites i paid 2k for this course a while back and pow ! A spit load of questions answered .

RSLogix 5000 Training | PLC II | George Brown College

simulator plans :

A slc 500 with rtd , analog in , analog out and a few more discrete cards & PC w/driving software from this asian fella for $400 .

I have an rtd adjacent to a panel fan , portable heater facing thermocouple , VFD and motor . Id like to set up a closed loop servo drive and need some ideas please .

Nothing is operational at this point , only mounted on a board ( budget is always a concern ) Please follow up with questions or comments

best regards
SJ
 
I do not understand the question or what you are looking for in answers?


" Id like to set up a closed loop servo drive and need some ideas please "

That course , as informative as it is ... does not specify much in the department of PLC servo control. Assuming I would need a motor with a resolver or encoder as well as the controller to drive the motor . I'm not sure what else I would need or steps to program PLC to interface with it .

Thanks
 
Take a look at linuxcnc. Free, downloadable. Lots of help by forum or irc. Servo or steppers. Runs everything from sherline to rather decent sized machines. Tuning (servo) has P, I, D, FF0, FF1 and FF2. Also has a plc. (classic ladder). G code looks like a Haas at least some of the time. It also has a simulator so you can play without having servos set up. HTH.
Some of the wiki is pretty dated.
 
Doesn't seem like you're explaining your case very well. You're wanting to build a PID temperature loop to control the speed of the fan? I'm an Automationdirect guy, so I can't help with Allen junk, but I'm sure they're people here that can help you if you explain exactly what you want your system to do.
 
Sorry for the late response but here is where I'm at on my simulator , its been very educational

You will need an analog input for the RTD. The VFD depending on what it is might have a couple of various ways to control it. You could use an analog output signal from the PLC to control the fan speed. You will also need a digital output card to control the VFD for fan on and off.

There is also the possibility that your VFD will require a network form of communication via Modbus, Fieldbus, or standard TC/IP. These will all require some sort of data block structure to be setup in your program to work. If you go this route, you can read a lot of VFD operational parameters in real time.

The analog output is much simpler to implement but more limiting.
 
Looks like you work in maintenance in a plant? The plant has AB PLCs and drives that you are learning to maintain? Is that the context you are in?

Understanding context is the only way we can answer your question. If a closed loop temperature control is what you are trying to do with a PLC, with the item monitored being a thermocouple and the item controlled being fan speed. You need to describe whether the control variable is an analog speed control for the VFD or a digital On/Off control.
 
The way I understand his post, he is looking to get into motion and he needs ideas.

There is 3 ways to interface "synced" motion with a PLC (that I can think of right now)
1, Pulse train output, usually open loop used with steppers.
2, Digital communication, for Rockwell I think its Ethernet/IP or SERCOS.
3, Analog 0-10 volt output card, and an additional encoder input card, this will allow you to use any brands of servo drive.
 
The way I understand his post, he is looking to get into motion and he needs ideas.

There is 3 ways to interface "synced" motion with a PLC (that I can think of right now)
1, Pulse train output, usually open loop used with steppers.
2, Digital communication, for Rockwell I think its Ethernet/IP or SERCOS.
3, Analog 0-10 volt output card, and an additional encoder input card, this will allow you to use any brands of servo drive.


Yes sir , exactly ....... would this be the kinda counter card I would be looking for ? Allen-Bradley 1746-HSCE SLC 500 Ser. A High Speed Counter Encoder 1746HSCE | eBay

MY analog output card is currently driving a VFD , its it possible to use another channel on that card or is it dedicated to 1 purpose only ? With an analog output card & encoder input card is it fair to say that all I would need is a servo (with encoder ) & controller to be operational ?

Currently , My first program involves 73 lines of code where the heater kicks on & off for 10 sec @ a time & rotation of the motor is proportional to temp. @ thermocouple . Its not all that proportional though , more like " every 10 degrees the motor gains or losses 5% more or less rpms " .

Like I said , I am very new to this and learning as I go .
 
Temperature control is not motion control.

I hate to break this to you, but with a SLC500 you simply cannot do “motion control” without a dedicated motion control card. The card you linked will allow you to monitor position (poorly) and non deterministically . . . but you won’t control motion with it any better than a drunken squirrel could.

look at these for a way to do limited motion with a SLC . . .

PLC Hardware - Allen Bradley 1746-HS Series A, Used in PLCH Packaging

1746-HSTP1 Replacement Motion Controller Module for Allen-Bradley SLC500 | AMCI

I would call these “bubba motion” solutions that aren’t particularly capable.

As stated above, you can do open loop control with a frequency output to a stepper.

The SLC 50x family of PLC’S cannot do motion over network (in Rockwell speak this is CIP motion with the current generation PLC’s).

The SLC can do analog control with encoder feedback only by using a dedicated motion card. And in that case you are not programming the motion in ladder, you are programming it in the dedicated card with a different application and then using ladder to write parameters and control bits while monitoring status of the card.

If you are serious about learning motion on the Rockwell platform, you need to start with something from this century rather than 25 year old technology. Get a CompactLogix with CIP Motion and a PowerFlex or Kinetix drive. Playing with a SLC500 and trying to do motion is like playing with a Commodore computer and hoping to do 5-axis CAM work.

Here is a recent 32 axis motion system totaling roughly 200kW of power the largest of which is a 100kW motor. Kinetix 5900 drives over CIP motion controlled from a GuardLogix PLC . . . most ACVector motors with 2million+ count per revolution encoders running in closed loop position control. A few open loop AC motors, a few servos, and a few ACVector motors with 4096 count / rev quadrature encoders. This is a retrofit for a Kirkland brand bath tissue winder capable of 2500 fpm continuous operation.

Google Photos

3FD5EA34-1A85-401B-909C-BEF5CB6C5E1C.jpg
 
Here is a recent 32 axis motion system totaling roughly 200kW of power the largest of which is a 100kW motor. Kinetix 5900 drives over CIP motion controlled from a GuardLogix PLC . . . most ACVector motors with 2million+ count per revolution encoders running in closed loop position control. A few open loop AC motors, a few servos, and a few ACVector motors with 4096 count / rev quadrature encoders. This is a retrofit for a Kirkland brand bath tissue winder capable of 2500 fpm continuous operation.

If you don't mind sharing, what drove the choice for AB on this one instead of Siemens?
 
Temperature control is not motion control.

I hate to break this to you, but with a SLC500 you simply cannot do “motion control” without a dedicated motion control card.

I would not say cannot do and for sure temp control is not motion control. One of these moves so slowly, the other gets out of control and does bad things fast.

I did a 12 axis DC servo simultaneous control on a PLC3 in the early 80's with no motion control cards.
To say that it was frustrating would be an huge understatement. I was brought in after 3 other control engineers had failed and I thought "this can't be that hard".
Oh to be young and foolish, I was so wrong in this thinking. The poor little thing also had the rest of the transfer line and robots to control, the I/O cabinets alone 40 feet long.
On the plus side it taught me a lot about the digital and analog domains and system electrical and mechanical response.
One hell of a under the gun learning curve of theory vs practice whit the line built and pressure from "We need to build this car in production quantities NOW"

It is possible, it is not a good idea nowadays unless you like a year or two of sleepless nights.
KISS, offload the work to subsystem made to handle it.

Temp control is not all those problems. There is a huge response lag. This means on the way up being early start, on the way down early stop.
You need to know those leads and lags for your system,
Bob
 
Customer plant standard - this is about the 30th system like this we have deployed. We started out with Delta Tau motion on top of Control-Techniques drives with the DT motion controller in a VME rack with an Allen Bradley PLC5VME PLC. Next generation was ControLogix CIP on top of PF755 and Kinetix Servo drives with Siemens ALMs powering drives on a common DC bus so that we had bidirectional power and no need for dynamic braking resistors. Latest generation is as shown in the photo above.

Here is the second generation SiRock panel . . . Shared album - Ken Brown - Google Photos


The Siemens ALMs are 120kW each and the customer could monitor power for the machine with a high degree of precision. We have had some customers apply for energy credits when deploying drives in this manner because of the energy savings afforded through common bussing, elimination of dynamic braking resistors (also a paper dust ignition hazard) and regenerative braking during stops that pumps energy back onto the utility with IEEE 519 compliant waveform quality.
 
I would not say cannot do.
I did a 12 axis DC servo simultaneous control on a PLC3 in the early 80's with no motion control cards.
To say that it was frustrating would be an huge understatement. I was brought in after 3 other control engineers had failed and I thought "this can't be that hard".
Oh to be young and foolish, I was so wrong in this thinking. The poor little thing also had the rest of the transfer line and robots to control, the I/O cabinets alone 40 feet long.
It is possible, it is not a good idea nowadays unless you like a year or so of sleepless nights.
KISS
Bob


Agreed . . . however, my point was, you can also do a 5-Axis CAM solution using a Commodore computer . . . but who would want to?
 
Agreed . . . however, my point was, you can also do a 5-Axis CAM solution using a Commodore computer . . . but who would want to?

Agree not a good idea now and only crazy people would want to but.....
Oh do not ask. at the time not much else low cost to use.
My first voice recognition system on a Commodore 64. My first one axis servo sg on a COSMAC ELF, My first 3 axis SG on this.. ZX81 - Wikipedia
 
My first motion application was done on an SMCC (Smart Motion Control Card) which had the capability of creating sinewave current references for PM and Induction motors. My boss got the bright idea of taking an Eaton 5000 Dynamatic drive and putting an analog current regulator in front of the gate driver board on the inverter bridge . . . viola . . . a home made vector drive that you had complete control over the commutation algorithm and my life has never been the same. That was almost 30 years ago . . . :codger:

I remember showing a quartz clock movement at a trade show on a 100 HP Reliance AC motor . . . that was a lot of fun to watch people try to figure out how we got that motor to be the second hand on a clock.

https://www.amazon.com/DELTA-TAU-602163-101-SMCC-VME-MC096-012-2-BOARD/dp/B01D1GBJOK

From there I started using PMACs and then UMACs and then the wheels fell off with respect to reliability and our largest customer said you can use any motion controller you want as long as it has an Allen Bradley label on it. :bawling:

We adapted to bubba motion and it has gotten marginally better over the years. We still use DT on the hard stuff (picometer resolution stages for electron beam microscopy) . . . and we use Siemens whenever we can for complex motion . . . and Control-Techniques when it makes sense for stand along single axis systems. I have a DT PMAC based engraver in the basement that is still fully functional with 6 inches of Z-travel so can be used for more than just engraving.

Delta Tau has since been purchased by OMRON and they are kick butt again with respect to reliability and I wouldn't hesitate to use them again. Fantastic motion trajectory generator with best in class axis coordination capabilities. The electron beam microscope stage we did a few years ago could close 4 user written 5-phase servo loops at 20kHz while using less than 10% of the CPU bandwidth . . . quite the motion engine.
 








 
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