Rockwell Automation RECOMM-PBUS PROFIBUS Communications Module - Manual (Page 56)

6-4 PROFIBUS Communications Module
6.3 Using Logic Command/Status
When enabled, the Logic Command/Status word is always word 0
in the I/O image. The Logic Command is a 16-bit word of control
produced by the scanner and consumed by the module. The Logic
Status is a 16-bit word of status produced by the module and
consumed by the scanner.
This manual contains the bit definitions for compatible products
available at the time of publication in Appendix C, Logic Command/
Status Words. For other products, refer to their documentation.
6.4 Using Reference/Feedback
When enabled, Reference/Feedback always begins at word 1 in the
I/O image. The Reference (16 bits or 32 bits) is produced by the
controller and consumed by the module. The Feedback (16 bits or
32 bits) is produced by the module and consumed by the controller.
The size of the Reference/Feedback is determined by the drive and
displayed in module parameter 6 (Ref/Fdbk Size).
6.5 Using Datalinks
A Datalink is a mechanism used by SP600 drives to transfer data to
and from the controller. Datalinks allow a parameter value to be
changed without using an Explicit Message.
When enabled (optional), each Datalink consumes either two 16 or
32-bit words in both the input and output image depending on its
size. The size of Datalinks (16-bit words or 32-bit words) is
determined by the drive and displayed in module parameter 7
(Datalink Size) in the module.
6.5.1 Rules for Using Datalinks
• Each set of Datalink parameters in an SP600 drive can be used
by only one module. If more than one module is connected to a
single drive, multiple modules must not try to use the same
Datalink.
Size Valid Values In I/O Image Example
16-bit -32768 to 32767 Word 1 Figure 6.1
32-bit -2147483648 to
2147483647 Word 1 and
Word 2 Figure 6.2