SLC5/05 INT messaging to Contrologix 5571

[klawson5]

What is the best way to Read INT data from Control logix 5571 back to SLC 5/05. We are doing a MSG read N107:10 with length of 14 to the COntrol logix unit. New to the Control Logix world and Service tech is having some trouble. Any help appreciated.

 

[sthompson]

What is the best way to Read INT data from Control logix 5571 back to SLC 5/05. We are doing a MSG read N107:10 with length of 14 to the COntrol logix unit. New to the Control Logix world and Service tech is having some trouble. Any help appreciated.

Welcome to the Forum!

You will have to do a Write from the ControlLogix, as the SLC5/05 MSG Instruction can't Read from the ControlLogix. Make sure the Data in the ControlLogix is INT and not DINT, or you will get an Error.

Stu....

 

[klawson5]

Thanks for the help and off and running.

 

[sthompson]

Thanks for the help and off and running.

No problem, glad to hear you got it running.

Stu....

 

[daba]

Welcome to the Forum!

You will have to do a Write from the ControlLogix, as the SLC5/05 MSG Instruction can't Read from the ControlLogix. Make sure the Data in the ControlLogix is INT and not DINT, or you will get an Error.

Stu....

Incorrect - The SLC can read the ControlLogix with no problems.

But of course SLC can only read legacy "data-table" style addresses, which the ControlLogix doesn't have, so the controlLogix has to have a "mapping" entry ....

Example....

SLC wants to read an INT[10] array tag from the ControlLogix called ProductionData

SLC message read instruction reads "N20:0" length 10.

ControlLogix has to have an entry in the "PLC/SLC mapping table" to redirect the file "20" to the tag ProductionData

 

[sthompson]

Incorrect - The SLC can read the ControlLogix with no problems.

But of course SLC can only read legacy "data-table" style addresses, which the ControlLogix doesn't have, so the controlLogix has to have a "mapping" entry ....

Example....

SLC wants to read an INT[10] array tag from the ControlLogix called ProductionData

SLC message read instruction reads "N20:0" length 10.

ControlLogix has to have an entry in the "PLC/SLC mapping table" to redirect the file "20" to the tag ProductionData

You are absolutely correct Daba. However, it requires setting all the SLC/PLC Memory Mapping Offline, and Downloading it, which isn't always possible. I certainly could have worded my response better.

The ControlLogix/CompactLogix PLCs can Read/Write to the older PLCs natively, whereas the ControlLogix SLC Mapping just fools the older PLC into thinking it is Reading/Writing to an older Target PLC (i.e. SLC).

Stu....