I’m trying to decide what to choose for a machine HMI on an upcoming project, either Red Lion HMI or Ignition Edge. However, I think I just found the answer based on limitations for using Ignition edge.
I’m copying a project I did about 9 years ago, using a Red Lion HMI, re-branded to Eurotherm. There is a SLC 5/05, which I’ll upgrade to Compactlogix. 4 separate temperature controllers, Eurotherm Mini-8. And 2 Eurotherm pressure controllers. I’m guessing this method of distributing the temperature and pressure control will not work with the limited number of controllers that can be connected to the Edge version. Can someone confirm this?
Edge is by default limited to connection to 2 devices, however its an extra US$200 to add additional connections
Ok, thank you. So… an extra $1,000 for 7 connections total is what I got from that.
I’d speak to your sales rep
Also, if you have a Logix processor and an HMI, why do you need separate temperature and pressure controllers?
Well that’s another question I’m trying to answer, at least for myself. The first machine was purchased by my customer on the 2nd hand market in 2012. All together, it’s a huge machine, with two co-extruders. They presented all the separate panels and components to me and asked if I could make it work. I had no experience with plastic extruders. I worked on it for the next several months with an electrician and we got it running. The machine’s original equipment had the SLC 5/05, and separate Eurotherm “Process Supervisor” for all the temperature zones. When originally presented with the components, I realized the Process Supervisor was obsolete and non-repairable thru Eurotherm. So, I found a multi loop controller I could use to replace it (Mini-8). The pressure controllers were separate as well. There are 36 temperature zones on the extruder (separate from the Roll Stand). I know the CPUs these days are far superior to the old SLCs, but I have no other reference to what the best method is. There are 36 temperature loops, 11 of them are heat/cool. 2 pressure loops. I’m also wondering if there is a cost/per loop advantage one way or another.
I’m really hoping to find someone with some experience with this question.
I’ve used a CompactLogix in several projects to drive multiple heating loops off of high-power Solid-State Relays. (Not extruders, but similar high thermal mass.) The ones that switch only at zero-crossing are the best. I would pulse-width modulate in AC cycle intervals, and would shift the ON-times of the zones to minimize power spikes. You won’t miss the external controllers.
From my files: Carlo Gavvazzi RJ1A23D20U solid-state relays were the bomb.
I’ve never looked that deeply into the SS relays. I took a pic of the 4 zones in the co-extruder. If my picture shows, you’ll see they are Crydom CKRD4830. Using the separate zone controller, I just hook them up to the PWM, 24vdc outputs and I’m good. Is there a simple way to shift the On-times using Studio 5000? I’m envisioning a stock function block available somewhere. Also, is there a special output card for PWM, or would you use a standard relay-output?
Do not use relay outputs with SSRs. The whole point is to have no moving parts. Use standard 24VDC outputs to drive the SSRs.
There’s no standard logic. Just count 8.3 ms periods across 10 seconds to get 1:1200 resolution. Adjust as needed.
One other piece of advice - just make sure the SSR inputs are compatible with the off-state leakage current of the PLC output module. I agree with not using relay outputs, but just changing to a solid state output card can be a problem if the off-state of the PLC outputs won’t turn off the SSR relays. You can’t assume this will work.