busarider29
Lifetime Supporting Member
https://www.beckhoff.com/en-us/support/download-finder/software-and-tools/https://www.beckhoff.com/en-us/support/download-finder/software-and-tools/
I presume by "dedicated controllers", you are referring to hardware temperature controllers(?). Today's PLC's (in lieu of maybe PLC2 of 1980's vintage) can easily do PID control via PWM'ing of On/Off control. It's easily done in RSLogix500, RSLogix5000, and TwinCAT-3 (the softwares I've done it with). Most of today's PLC PID's have something built in for PWM control, in lieu of only analog.
When I first started (8 years ago) at the company I'm at now, all of their fluid temperature control was via the controls engineer's own algorithm using PLC logic. It was messy, long, and more complicated than what I thought it needed to be. Worse is that it never worked well. A lot of overshoot on startup (or taking forever to get to SP), and then just continually hunting around the SP. Whenever I saw the logic in the code, I always thought - "Why not just make this way more simple (and better) by just using a PID instruction?? That's what it's there for."
My guess is that nobody there knew how to use the PID instruction (RSLogix500 or RSLogix5000), were too scared or lazy to go through the learning process, and/or were just scared off anytime they saw "PID", thinking to themselves, "Oh no, that sounds like Calculus!! Forget that!". Then one day a technician called me out to a machine to try and make the temperature control on it work better. That's when I said "Enough with this PLC logic. We're going to do this right and use a PID instruction!". Broke out the RSLogix Instruction manual and implemented it. Worked like a charm, and wasn't difficult to do either. The next day, the technician calls me out to look at his trending software. He tells me the Temperature SP is trending and shows on the trend chart but the Temperature PV is not. I say, "Yes it is. You can't see your PV trend because your SP trend is overlaid directly on top of it." He was so accustomed to seeing the PV trend appear as a sine wave hunting around the SP trend!
Since then, we've implemented PID for all of our machines for temperature control. If you have a decent PLC platform with a good instruction set, and most certainly if you're using the Beckhoff platform with TwinCAT-3 (which is my hard recommendation for PLC platform, which is a PC based PLC), you don't need dedicated temperature controller hardware.
For the OP if going the PLC route, this is all you would need:
PLC Hardware:
CX7000 - "Economy" and ultra compact PLC with integrated digital inputs and outputs.
EL3314 - 4 Channel thermocouple input module
EL6070 - License Terminal. All licenses for the PLC are stored on this.
EL9011 - Bus end cover
PLC software and licenses:
TwinCAT-3 XAE. This is the PLC engineering software that installs on your laptop. It's free, no license required.
TwinCAT-3 XAR. This is the PLC runtime software that get's installed on the CX7000
TC1200-0v10 - TwinCAT 3 runtime license for this performance level PLC (Note: You can just keep renewing the 7-day trial license until you're ready to purchase this license).
TF4110-0v10 - Temperature Controller PLC library license for this performance level PLC (Note: you can just keep renewing the 7-day trial license until you're ready to purchase this license).
For the PWM'ing of heaters, look at the Carlo Gavazzi line of SSR contactors. They are pricey, but on some models they have integrated monitoring of mains loss, load loss, SSR short circuit, and over-temperature, with 24VDC alarm output to notify your PLC.
The CX7000 is a newer product and may not be available immediately(?). If that is the case, then I would opt for the CX9020. That model does not come with integrated digital inputs/outputs, so you would need to add a module for those. Also, the part numbers for the licenses would change if you went with the CX9020 (different performance level), so keep that in mind as well. Hope this helps.
I presume by "dedicated controllers", you are referring to hardware temperature controllers(?). Today's PLC's (in lieu of maybe PLC2 of 1980's vintage) can easily do PID control via PWM'ing of On/Off control. It's easily done in RSLogix500, RSLogix5000, and TwinCAT-3 (the softwares I've done it with). Most of today's PLC PID's have something built in for PWM control, in lieu of only analog.
When I first started (8 years ago) at the company I'm at now, all of their fluid temperature control was via the controls engineer's own algorithm using PLC logic. It was messy, long, and more complicated than what I thought it needed to be. Worse is that it never worked well. A lot of overshoot on startup (or taking forever to get to SP), and then just continually hunting around the SP. Whenever I saw the logic in the code, I always thought - "Why not just make this way more simple (and better) by just using a PID instruction?? That's what it's there for."
My guess is that nobody there knew how to use the PID instruction (RSLogix500 or RSLogix5000), were too scared or lazy to go through the learning process, and/or were just scared off anytime they saw "PID", thinking to themselves, "Oh no, that sounds like Calculus!! Forget that!". Then one day a technician called me out to a machine to try and make the temperature control on it work better. That's when I said "Enough with this PLC logic. We're going to do this right and use a PID instruction!". Broke out the RSLogix Instruction manual and implemented it. Worked like a charm, and wasn't difficult to do either. The next day, the technician calls me out to look at his trending software. He tells me the Temperature SP is trending and shows on the trend chart but the Temperature PV is not. I say, "Yes it is. You can't see your PV trend because your SP trend is overlaid directly on top of it." He was so accustomed to seeing the PV trend appear as a sine wave hunting around the SP trend!
Since then, we've implemented PID for all of our machines for temperature control. If you have a decent PLC platform with a good instruction set, and most certainly if you're using the Beckhoff platform with TwinCAT-3 (which is my hard recommendation for PLC platform, which is a PC based PLC), you don't need dedicated temperature controller hardware.
For the OP if going the PLC route, this is all you would need:
PLC Hardware:
CX7000 - "Economy" and ultra compact PLC with integrated digital inputs and outputs.
EL3314 - 4 Channel thermocouple input module
EL6070 - License Terminal. All licenses for the PLC are stored on this.
EL9011 - Bus end cover
PLC software and licenses:
TwinCAT-3 XAE. This is the PLC engineering software that installs on your laptop. It's free, no license required.
TwinCAT-3 XAR. This is the PLC runtime software that get's installed on the CX7000
TC1200-0v10 - TwinCAT 3 runtime license for this performance level PLC (Note: You can just keep renewing the 7-day trial license until you're ready to purchase this license).
TF4110-0v10 - Temperature Controller PLC library license for this performance level PLC (Note: you can just keep renewing the 7-day trial license until you're ready to purchase this license).
For the PWM'ing of heaters, look at the Carlo Gavazzi line of SSR contactors. They are pricey, but on some models they have integrated monitoring of mains loss, load loss, SSR short circuit, and over-temperature, with 24VDC alarm output to notify your PLC.
The CX7000 is a newer product and may not be available immediately(?). If that is the case, then I would opt for the CX9020. That model does not come with integrated digital inputs/outputs, so you would need to add a module for those. Also, the part numbers for the licenses would change if you went with the CX9020 (different performance level), so keep that in mind as well. Hope this helps.
