What's the hardware I need to use LabVIEW PID to control some heaters?

[Top24]

I, I'm currently at a college project working on a software in LabVIEW to analise some heat sensors and with that information control some heaters.

I'm searching and trying to design a PID controler to control the heaters but what is the NI Hardware to connect to my computer/server and use the labview PID information to turn the heaters on?

I'm new at LabVIEW and I'm not sure about what to do I was just told that I need a PID controler to control the heaters but I'm not sure how to do the PID as well as the hardware required to control it.

Thanks in advance sorry about the messy text

[Jaggs]

I beleiev you are trying to do lot of things as a LabVIEW beginner.  Anyways to get started you will require the following:

1. LabVIEW software with PID toolkit

2. LabVIEW Controller, for a college project you can use NI-6008 and it should be ok or use any off the shelf third party Modbus hardware such as Galil Pocket PLC

3. Hardware to control the heaters such as  http://www.omega.com/pptst/SCR19.html .  Again I don't know the heaters so you may not even need this.  You can create your own low cost circuit by getting parts from radio Shack.

4.  Browse Ni website and you will find lots of VI examples which will demonstrate how to do a PID control

Good Luck!

[nathand]

I'm not sure about the choice of hardware suggested here. The USB-6008 has only analog voltage output (0-5V) and the Omega SCR power controller requires a 4-20mA current signal.

Instead, you can buy a device that support current output from another vendor (I've used ones from Advantech) and connect it to the Omega device, or you can buy an NI device that can generate a PWM signal (a counter/timer output) which you connect directly to a solid-state relay (SSR). You'll pay more for the NI hardware, but you won't need the Omega device so it may come out similar in cost.

[Top24]

Hi,

I already have PID toolkit, as the hardware my heaters will have to work with 24V DC (witch I still don't understand what's the diference in heaters between 24V DC and 230V AC ) but I have the heater and a computer and I require tounderstand how to control the heaters to a certain temperature. I already know I need PID software but i do not know what's the output of PID and what is the hardware to receive the PID output and control heaters input 😕

[nathand]

The PID toolkit is purely software. It has some numbers as inputs, and outputs a number. The meaning of that value depends on the inputs. Depending on how you set it up, that output might be percentage of full scale, voltage, current, duty cycle, or something else.

Of course, you also need a way to measure the temperature. Do you already have a device that can measure temperature, or are you looking for a piece of hardware that can both control the heater and measure temperature? How do you plan to measure temperature? What are the specifications for your heater? Why are you mentioning 230V AC, if you aren't using it?

[NIquist]

You probably shouldn't be worrying about hardware (or software for that matter) until you understand what PID servo control is all about.  Start here:

http://www.ni.com/pdf/manuals/372192a.pdf

http://techteach.no/labview/lv85/pid_control/index.htm

http://www.ni.com/white-paper/3782/en

Then do some Google searches for PID control in general.  There are also several NI tutorials and example for using the PID toolkit.  Once you have the general concepts down you can start applying them to your specific application needs.  THAT will allow you to determine the best hardware choices (or at least you'll know what questions to ask on this forum).

[Top24]

I mentioned 230V AC because I have to chose between 230V AC or 24V DC, I have both available but I THINK 24V is better can't explain why and that is one of the issues but... going to the subject, I already have a temperature control I'm doing the USB decode and code of the thermal resistor. My problem is really doing the heatinI already studiend a bunch of information about PID but what I still can't understand is how to control the heater with my PID output. I still haven't do the PID in labview but how can I have a look to my PID output graph if I don't know with hardware to connect between my heater and my computer.

As I told before I'm really new at labview and I don't know any of the NI hardware or even if it is better to me to create my own hardware (with I thought from the begining it was better due the costs) and if I need to make my own hardware how do I communicate with Labview. 

I'm having really troubles to try to explaind my question because I never ever used labview connected to hardware only in software so if anyone can help me (and understood my question lol) I would apreciate.

Thanks

[Henrik_Volkers]

I THINK you better go with 24V ... 230V can kill you.  (Well, really high current can be dangerous too, but to heat some senors, the power could be quite small)

The type of controller and power supply is meaningless until you (and we) don't know what you need to do. Heat ... ok, range , stability , mass to heat, speed of temp change needed.... ???

Say you want to use a TEC, than a linear control is prefered ..  but a 10 liter stirred water/oil bath with 2kW heater is fine with a ON/OFF control (in whatever pulse regime) 

McGyver would use the soundcard,an old hifi amp and  2m iron fence wire 😉

Bonuspoints if the heater emmits the four seasons ... according to the desired temperature 😄

[Top24]

Hi, I still do not know what is to heat (it was told to me it was to heat some kind of plates) I have 8 temperature sensors and 8 heaters and I need to control all heaters so a desired temperature the user input's 😕

[camerond]

Is the purpose of the project primarily to control the temperature(s) or control something with LabVIEW? What is your hardware budget?

From Omega you can get something like this and control it with RS-232. Of course this particular one controls only one heater. Worked fine for my project, though.

(mAybe now the link is right)

Cameron