Tag Design in RSLOGIX 5000 is confusing me

[asterof]

Basin[1].Chain[0].Valve.Status

Trying to figure out what this tag is made up of
Looks like Basin[0] is a array of dints
Chain[0] is an array of dints
but not sure what .valve.Status is
maybe this is a UDT ?

 

[Paullys50]

It looks like it's a cascaded UDT.

Basin[x] is an array of a UDT instance.
Chain[x] is a member of the basin UDT, this appears to be of another UDT type.
Valve is a member of the Chain UDT, and is of another UDT type.
Finally Status is a member of the Valve UDT.

Just look at the UDT definitions, should be easy to follow.

 

[asterof]

Can not look at UDT

They wont release the code to me
Trying to create an HMI project
with out the PLC code
Thanks

 

[Eriond]

In the program tags, the "XXX.Status" is normally some type of word (SINT, INT, DINT) whose value is determined by processor. If I am not mistaken, that value is read only and is used for troubleshooting. For instance, For the word tag "Valve", when you expand it in the tag editor, you should see "Valve.Data" and Valve.Status". Basin and Chain look to be Arrays. Could this be some pointer used in indirect addressing? How in the world do they expect you to generate an HMI program without the PLC program?

 

[Robobob]

How in the world do they expect you to generate an HMI program without the PLC program?

This was my thought too. Having all of the tags does not show you how they are used in the logic. This would be like building a house with nails and no hammer.
Bob

 

[jstolaruk]

In the program tags, the "XXX.Status" is normally some type of word (SINT, INT, DINT) whose value is determined by processor. If I am not mistaken, that value is read only and is used for troubleshooting. For instance, For the word tag "Valve", when you expand it in the tag editor, you should see "Valve.Data" and Valve.Status". Basin and Chain look to be Arrays. Could this be some pointer used in indirect addressing? How in the world do they expect you to generate an HMI program without the PLC program?

Status could be anything without knowing the UDTs. And thankfully in this case, indirect addressing (like pointers) is not supported.

Sounds like the PLC program authors are afraid to give up intellectual property but at the very least they should supply the UDT definitions and tag list.

 

[ASF]

"Here's a picture of a house. I'd like you to build one exactly like it. You're not allowed to look at the plans; all you need to know is that it has three bedrooms, two bathrooms, and purple carpet."