funkyhunky

Block transfer R/W in 5000???

3 posts in this topic

Converting a simple PLC 5 control system to 5000. Want to use a DHRIO contrologix module to monitor my PLC 5 and test my converted 5000 logix

 

Issue: the PLC 5 code has these "block transfer read write" functions in the ladder and the the converted 5000 program does not. What purpose do these BTR/W modules do in the PLC 5 (I read the manual and it confuses me) I don't even think there is a "block transfer module" in the PLC 5 chassis: just digital & analog inputs, and and analog output modules

 

1.What does BTR/W do in PLC 5

2.What do I need to do to make it work for testing my 5000 code when monitoring PLC5 inputs

3. Do I need to do anything with BTR/W when I scrap the whole PLC5 and replace it with contrologix

 

Thank you!!!

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I'm by  no means an expert, but here's what I know.

1) BTR/W instructions are used to configure and read/write values from/to analog in/output modules (among others).

2) If you're just using analog in/outputs that are configured into the ControlLogix I/O tree, you just have to decipher where the BTR/W instructions are interfacing with the PLC logic (typically N7 registers). To do a direct translation, you can replace the BTR/W instructions that read/write analog values with MOV instructions.

3) The BTR/W instructions should be removed.

 

Example BTR:

BTR.png.c03e75dca13396d93895b6586f154771

In this case, the BTR is reading status information from an analog input module. The information it reads is stored in N7:200-204

Double-click on "Setup Screen":

BTR_Setup.thumb.png.15864f4ababf995ecb29

To replace this with ControlLogix, you can either substitute the analog inputs everywhere N7:201-4, or use a MOV instruction to copy the analog input value to whatever tag N7:20x gets converted to.

 

I welcome further input from any BTR/W experts who wish to contribute. We have a great diversity of PLC5 setups in this plant so I have some idea of the possible variations. This example may not apply very well to your situation.

 

BTR.png

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BTR/W are implemented using MSG in Logix 5000.

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