Created Date: March 30,2009

Created by: KPrice

Sacman, we have used the 04THM T/C modules for temp controller in place of stand-alone temp controllers. They work well. To reduce noise, use un-grounded, non-exposed T/Cs. Use shielded, twisted-pair T/C cable, grounding the shield at only one end. Usually the most convenient good ground is in the PLC cabinet. Also, look at possibly using the TC/4-20ma transmitters. This would allow 8 inputs on (1) module. The PLC does allow for more control and trending/tuning of the control loops. Of course it also requires programming the PLC and the touch panel for your control, tuning, and trending. Hope this helps.

Created Date: March 30,2009

Created by: FACTSTech

Wade,

It is time to look into using a PLC for temperature control. You can time multiplex the heaters as to not incurr a huge startup current load. With a PLC you can decide which loads to turn on first to startup the plant.

There are several ways to accomplish your task. You can use the 205 series, F2-04THM, 16 PID loops, 405 series, F4-08THM, 16 PID loops and/or F4-4LTC (4 temperature controllers per module).

Created Date: March 31,2009

Created by: Sacman

Thanks for the quick responses.

I actually have a spare 205 in house but we are trying to standardize everything to the DL06 DD2. This PLC will handle everything we currently do and is relatively low cost. We can maintain a single spare to cover many applications.

I may eventually use the 205 as a Modbus master to centralize many of the critical processes in the plant but this is down the road a ways.

It looks like it is well worth investing in a single module to test the process and then proceed from there. I have to be able to prove my case to those that matter so I will likely replace one more Controllers on one of the non time critical machines and run the PV signal in parallel with the Controller so I can prove that my logic works and the temperature is being properly controlled.

I will try to keep this post updated with my results. Maybe this will help someone else in the future.

What I am going to continue to focus on for the time being is perfecting my interface with the Solos. Whatever happens, I won't be able to convince them to undo the modifications we just made to the first machine less than 3 m onths ago. We also happen to have a spare 6 " color C-More on hand. Not the best size but it looks great with the analog meters.

Thanks again,

Wade

Created Date: April 04,2009

Created by: RogerR

Wade,

As suggested earlier in this thread, the 205 series PLC with its 16 PID loops along with F2-04THM Input Modules will function well for this application.

I have installed this setup on quite a few plastic extruders myself. Usually the PLC also contols the part or all of the production line.

An additional feature that I incorporate is an adjustable proportioning output.

Using a solid state relay or conventional contactors to the heaters or cooling, the PID output can be latched or interupted with logic to provide a minimum and maximum output time for any given time period.

On solid state relays I usually use a one second period and on contactors a ten second period to increase contact life.

Using this feature, the overall wattage can be reduced by one half by making the maximum time one half second in the one second time period. This can be useful to ramp up a zone slower or to tune it in with other zones that may heat faster or slower.

Along with the proportioning timed output, you can phase the outputs so that they are turning on and off at different intervals. This keeps the peak current draw down. If you had a modbus master PLC, it could even even out the different lines for amp draw.

The 205 PID loops have a ramp/soak feature, but I have found this logic approach to be easier to manipulate to the exact situation on the machine.

RogerR

Created Date: April 05,2009

Created by: rawelk

Another possibility

Thanks for the quick responses.

I actually have a spare 205 in house but we are trying to standardize everything to the DL06 DD2. This PLC will handle everything we currently do and is relatively low cost. We can maintain a single spare to cover many applications.

I may eventually use the 205 as a Modbus master to centralize many of the critical processes in the plant but this is down the road a ways.

It looks like it is well worth investing in a single module to test the process and then proceed from there. I have to be able to prove my case to those that matter so I will likely replace one more Controllers on one of the non time critical machines and run the PV signal in parallel with the Controller so I can prove that my logic works and the temperature is being properly controlled.

I will try to keep this post updated with my results. Maybe this will help someone else in the future.

What I am going to continue to focus on for the time being is perfecting my interface with the Solos. Whatever happens, I won't be able to convince them to undo the modifications we just made to the first machine less than 3 m onths ago. We also happen to have a spare 6 " color C-More on hand. Not the best size but it looks great with the analog meters.

Thanks again,

Wade

I haven't used Solo instruments for temperature control, but did use three of them recently to detect motor winding temperatures (RTD feedback), and cause a shut down if temperatures went too high.

Recall seeing a 'run/stop ' option in the configuration software. The manual doesn't go into it in detail, but it seems that toggling this (1=run; 0=stop) in Modbus register 2069 (page 78 in the PDF manual) would allow you to a "soft " power-up using your existing Solo controllers under PLC control.

The basic idea would be to cycle through each (or every two or three) barrel zones sequentially every 10 seconds or so until they were about halfway between the lower PID band and setpoint.

Another method would be to place the 'soft start ' zones into manual mode, and program the PLC to sequence them between 0% and 100% output until they were closing in on setpoint, then switch over to PID control.

Created Date: April 07,2009

Created by: Sacman

For anyone following along here.

To update, I have found the run stop function and I am using that to set them all to stop mode on system startup. If the user selects Run mode, they all go to run mode and function using their internal PID. If the user selects Startup, I will set them in a time loop where I will allow the PID to function as normal but for a set amount of time as I cycle through the ten hearer zones. I haven't written this part yet.

Anyway I have a C-More question regarding recipes. When I go from the start screen, I go to a screen with an analog meter and a few other piece sof info. I want to use recipe buttons to cycle through the heaters. I only have a 6 " screen so there is not enough room to display them all at once.

I don't want to select the heater, simply cycle through hence the use of the recipe button versus recipe select. When I first go to the screen, since everything is tied to internal tags for recipe lookup, there is no data. Is there a way to have an initial recipe loaded?

The only way I can think to do it is to tie the items to actual PLC tags and then rereference the PLC tags in the recipe. Is this legit or will it try to overwrite my PLC registers for the first zone with data from the other zones as I cycle through. This won't work if this is the case as I suspect it is.

I tried using an event but it does not seem to do what I need it to do. There is a chance I am using this wrong as I have not used the events before.

My intent is to have 10 recipe buttons on the screen and make them invisble until the appropriate time. I think this will work but I really need to fill in that first one.

Thanks again,

Wade

Created Date: April 11,2009

Created by: Sacman

Ok, so here is what I did instead. I have an individual screen per heater and simply step through them.

I have two analog meters on each screen. One with a 0 to 600 range and one with 300 to 600. I make them visible or invisble based on a compare in the ladder logic. This is working great but I have run across a bug in the analog meter object.

I sent a tech support request in but in case anyone has seen the same issue or if anyone is willing to try this and see if I am doing something worng.

Take an analog meter on a C-More. I am using a 6 " color but it should not matter. The color may matter though to see the problem.

Set the range from 300 to 600

Set the alarms as static to the following:

LowLow: 325 Red

Low: 390 Yellow

High: 430 Yellow

HighHigh: 500 Red

The low end seems to work fine but the high end does not work correctly. The Yellow band does not show. The band shows but the whole band is in red.

If I change the top band (highhigh) to some off color like blue. It won't even change the color of the band. It is still red.

I have the latest (2.41) firmware and software.

Any ideas?

Wade

Created Date: March 30,2009

Created by: Sacman

I have several plastic extrusion machines that use multiple heat zones. Most of them are using Ogden Temperature controllers but we have recently transferred one over to the Solo units. I have been working on using a DL06 to communicate with the Solos and have had plenty of success.

However, the smallest of our extruders has 6 temperature zones and the largest has 13. We have discussed transitioning all of the machines to the Solos but we need to modify the way they start up due to energy concerns. Right now all 13 zones come on at once and if we are starting multiple machines, this can be a significant drain on power. We are charged a usage charge based on our peak 30 minutes. This peak is, without fail, tied to our Sunday night startups.

To get to my point, in order to have more control of the start sequence, I have been looiking at using PLC control. This is great for the line that already has the Solos but the Ogdens are not controllable. So the cost starts to rise significantly.

Now to the question. I have looked at investing in an F0-04THM thermocouple module and testing it within our operation. Before making the investment, has anyone tried to replace existing Temp Controllers with this module and have you had any success? Using this method could potentially cut my costs in half.

Any pointers would be appreciated.

Thanks in advance,

Wade