I need to convert a RSLogix Program from Celsius to Fahrenheit, I have had the file on here before and was going to look into a different way to go about it without having to change the entire file but it looks like I don't have a choice. I know I have to change the I/O inputs to fahrenheit. I am guessing I also need to change any other block associated with temperature readings. I am not sure what all blocks I need to be looking for. Any help would be appreciated, I have the RSS file if I need to upload it. I also have an old file that is similar that has everything labeled if that will help.
Converting a Logic File from Degrees Celsius to Fahrenheit
- Thread starter tkessler8
- Start date
Here is the RSS current file it won't let me upload the old file even compressed it says it is too big. This is an Allen-Bradley SLC 5/03 with a PanelView550 operator interface. If anyone knows how to make the PV550 display in Celsius without changing the Logic that would be great too. We just can't trust our operators to make the conversions and the conversion will add error to our process.
harryting
Lifetime Supporting Member
You already know this part:
IO Configuration - Select card 8, thermocuple input -Configure - Change each channel from C to F.
Since it's card 8, the temperature will go in I:8.x so you need to go to the data table for I:8.x and search each channel, I:8.0 to I:8.3 and see those words are being used.
To make sure, also look up the word location from the Panelview side, see where the display goes to then see how those words comes from.
IO Configuration - Select card 8, thermocuple input -Configure - Change each channel from C to F.
Since it's card 8, the temperature will go in I:8.x so you need to go to the data table for I:8.x and search each channel, I:8.0 to I:8.3 and see those words are being used.
To make sure, also look up the word location from the Panelview side, see where the display goes to then see how those words comes from.
JRoss
Lifetime Supporting Member
I can't remember if the Panelview Standard has tag scaling. If it does, just modify the Panelview to do that for you. 0-100C scales to 32-212F
If not, maybe it's time to upgrade to a Panelview Plus. The Standards have been out of production for years, and the cost of the new hardware may be offset by the time you would save rewriting the PLC. There is a conversion utility that does a half-decent job, and the PV+ has tag scaling.
If this isn't an option, then I would just put math in the PLC to rescale the HMI values only. Changing units over completely could have unforeseen complications, like needing to re-tune PID loops.
If not, maybe it's time to upgrade to a Panelview Plus. The Standards have been out of production for years, and the cost of the new hardware may be offset by the time you would save rewriting the PLC. There is a conversion utility that does a half-decent job, and the PV+ has tag scaling.
If this isn't an option, then I would just put math in the PLC to rescale the HMI values only. Changing units over completely could have unforeseen complications, like needing to re-tune PID loops.
It looks like I:8.x is only in Ladder 2 Rung 30 but I don't know what to do to it to make it Fahrenheit they are ADD modules and then it doesn't appear anywhere else in the logic. I had been told before on here to change Input Min and Max on Rung 31 in Ladder 2 and those have a totally different destination. It seems like it should just have something to do with the SCP and PID blocks but I am not sure.
harryting
Lifetime Supporting Member
Once you change the card configuration from C to F, then it's in F.
It's an educated guess that the logic you are talking about are "fudge factor" as I like to call them to correct the temperature. However, that's only a guess. The problem is that the "corrected temperature" or whatever they are also goes go to perform a lot of other functions and you need to find out what those functions are and if you also need to make all those in C as well in the logic. Yes, it will be a lot of investigative work.
It's an educated guess that the logic you are talking about are "fudge factor" as I like to call them to correct the temperature. However, that's only a guess. The problem is that the "corrected temperature" or whatever they are also goes go to perform a lot of other functions and you need to find out what those functions are and if you also need to make all those in C as well in the logic. Yes, it will be a lot of investigative work.
NetNathan
Lifetime Supporting Member
Math calc:
(C x 2) -10% +32 = F
(C x 2) -10% +32 = F
bernie_carlton
Lifetime Supporting Member + Moderator
If the only reason for the Celsius to Fahrenheit conversion is for display then definitely do it there. The standard Panelview does have tag scaling. Is the process otherwise we'll controlled? If so don't touch the PLC program.
Thanks for all the responses guys I was out of the office yesterday afternoon, and yes the only reason for changing it is for the display on the Panelview550 our charting system already does in Fahrenheit and the process is well controlled. How do I do tag scaling on the PanelView....also what exactly is tag scaling?
Bit_Bucket_07
Member
I'd recommend that you hire a qualified programmer to do this for you.
JRoss
Lifetime Supporting Member
Open up the Panelbuilder project, open the numeric object that you want to change, and click the edit tag button. There is a scaling and offset in the lower left hand corner.
Scaling is simply algebra to convert one unit to another. Remember your formula y=mx+b. The "Scaling" is the "m", and the "Offset" is the "b". So to go from C to F, set Scaling to 1.8 and offset to 32. You'll have to do that for every temperature tag on the HMI.
Scaling is simply algebra to convert one unit to another. Remember your formula y=mx+b. The "Scaling" is the "m", and the "Offset" is the "b". So to go from C to F, set Scaling to 1.8 and offset to 32. You'll have to do that for every temperature tag on the HMI.
JRoss
Lifetime Supporting Member
Well, that's a problem. You need Panelbuilder32 to modify the Panelview program. I don't see how you can get around that. Even if you do the scaling in the PLC, you have to change the "C" on the screen to "F", or you will make the confusion worse. Contact your Allen-Bradley distributor to see if they can either get you the software or recommend an integrator to help you out.
Similar Topics
Looking for info on converting RSLogix 500 file to RSLogix 5000 format. 1747-L552 CPU is being changed out with the 1769L35E
Hello, I have to update some PLC firmware (FX1n), the devices out on the market are reflashable via rs232. I cant find where the GX developer...
Hi there! I am new to PLC's, and I have undertaken the task of converting a primarily pneumatically-operated machine to electrically &...
Hi all,
Please understand that I am not good at English.
I have plan to project with one of our customer have the Ls XGB-XBC-DR60SU PLC.
This PLC...
I am looking to converting the Gem80 PLC logic in to Rockwell PLC. I need GEM80 Instruction Manuals, and documents that help you to understand the...