Les67 (Customer) asked a question.
Is there anyway to make these Min and Max entry ranges some kind of variable? Would like to be able to adjust these ranges from a password protected screen. The idea I am working with is a universal servo control application. The linear actuator comes in differing lengths so would be nice to be able to connect, power up, and commission the system with out having to plug my laptop and/or software into the panel. Kind of like a one size fits all thing and all a field technician has to do is select the configuration requirements. It also sets up the controllers to be cross compatible with any actuator with a simple re-configure.
Currently, I am the only one doing this in our company, but I want to pass this duty off to the manufacturing facilities maintenance personnel. One issue is the skill to hook up and then give access to the technician for this simple adjustment is a bit scary to me. Most staff is good in the mechanical and general electrical, but PLC and HMI...
Thoughts? Work around?
One tedious idea is to make a bunch of numeric entry objects and the set the visibility by configuration. But I have 5 length versions and may have even more to come.
I don't believe you can do (exactly) what you are asking. But, as a work around, you could have some variables defined in the password protected portion of the HMI, and then have the PLC logic program "enforce" those variables as the range, if user enters out of range variable, force it to be within the range. You could also pop up a indicator when this occurs. Not ideal, but seems like a a workable workaround.
I would try doing this on the PLC side. Not sure what PLC you have. Constrain or limit would be functions to look for. I've done this between an EA9 and Prod 1000 and the time it takes to set the wrong value and have the PLC correct it is instantaneous. you could then use the tags that define the limits in a numeric display as your min max.
Andrew
It would be nice if it were but as a workaround you can just put some logic in the PLC that looks at the entered value and compares it to a min/max value that can be set elsewhere in a protected area on the screen. If entered value is out of range low it just overwrites it with the min and the same for out of range high.
If using P suite there is a limit function that will do it all for you. In AB there are limit tests. Do More has Clamp.
It would be real useful if the "Range" setting the the Numeric Entry would allow tags that look back to the plc for the value. Maybe something for future update?
I have been wanting this feature for a long time.
We are an OEM and I use the same program on a variety of machines. I already have a section in the HMI & PLC where I specify the configuration size of the machine, but on the setup pages for stroke adjustment (numerical) I need to change the MIN & MAX limits manually for each machine axis.
It would be great if I could use the same variable I use in the PLC program in the HMI Min/Max section.
Create multiple numeric entry objects, each with their own MIN and MAX ranges, and control their viability through a numeric variable you set in your password-protected screen. Stack them on the user screen, and only the one you select will be visible.
In addition to not being truly dynamic, this approach will also have a decent performance hit as stacked objects with visibility tags tax the CPU.
For a dynamic approach, PLC limiting is the only choice. This does not display properly on the HMI though for the users. To address this, you should be able to create your own numeric entry keypad with a min and max. However, you'll need to detect when operators are entering a value and which value they are entering for this to work properly. It likely can be done, I haven't tried and I am not going to.
If you need to stack 20+ objects, there's a noticeable performance hit. If you need to stack a few, it's probably fine depending on what else is happening on that screen. But yes, the proper way to do this involves AD updating the C-more software to allow for MIN and MAX to be variables.
You can't do it with the EA9, but it is a standard feature for the CM5 panels.