Ethernet ip explicit message/scattered read

[Dale87]

We are going to pull 5-10 INT parameters out of 6 soft starts via explicit messaging in logix 5000. It's the only way we can read these over eth/ip. How do most guys handle this. Is it easier to just write 60 explicit message instructions. How do you time those 60 different instructions? Is there a way to pull multiple instances out with a single message instruction? Do all eth/ip devices support scattered read?

 

[Ken Roach]

What exact make and model of soft start are you using ?

Are any of the parameters available in an Assembly ?

The term "scattered read" reminds me of a feature built into A-B VFDs and soft-starts since the SCANPort days, where a specific message (or object, once CIP came along) could request a list of parameters by number, and receive an response containing those values.

 

[Dale87]

What exact make and model of soft start are you using ?

Are any of the parameters available in an Assembly ?

The term "scattered read" reminds me of a feature built into A-B VFDs and soft-starts since the SCANPort days, where a specific message (or object, once CIP came along) could request a list of parameters by number, and receive an response containing those values.

They are Benshaw EMX4I with Ethernet IP cards.

 

[JeremyM]

From the manual.

It looks like you'll have to use an iterative GetAttributeSingle message.

 

[AlfredoQuintero]

The technical documentation writers at Benshaw may need to improve their verification process.

 

[Ken Roach]

Good eye, Alfredo !

It is common for these sorts of devices to use Assemblies to group together similar diagnostic and operational data for reading by a PLC, even if those Assemblies aren't part of the cyclic I/O connection.

But my review of that manual comes to the same conclusion as Jeremy: they don't have any Assemblies to group the data together, and the Vendor-Specific classes they use to implement register access only support Get Single and Set Single, not Get All or another service that would read a range or group of registers.

 

[JeremyM]

Good catch, indeed. They also seem to have an instance for what what would normally be an attribute. Then it’s weird they list GetAttributeAll as a service for the vendor objects but also indicate it just works for common Identity.

Maybe try GetAttributeAll, anyway?

 

[Contr_Conn]

It looks very strange that they are incrementing instance numbers instead of attributes.
Instance number should be the same. Since we see obvious typos in their manual when it comes to service codes, it’s possible that they simply swapped two columns (Instance and attribute) and Get All for the Instance 100 will get you all information.