Parameter Protocol - Allen-Bradley PowerFlex 20-COMM-P User Manual

Parameter Protocol

This protocol uses 4 words in the Profibus I/O area. Requests and responses
are a handshake procedure and cannot be batched, meaning that if the
master sends a request, it has to wait for the response before sending a new
request.
With this protocol you can do the following:
• Read 8-bit, 16-bit, or 32-bit parameters from any DPI port
• Write 8-bit, 16-bit, or 32-bit parameters to any DPI port
• Read the Host Fault object
To enable this protocol, set adapter Parameter 23 - [Parameter Mode] to
'1' (DPI Par Prot), which is the default.
Figure 6.2 Parameter Message Format
Bit 15...12
Parameter Access
RC
Word 1 (PCA)
Parameter Access
Word 2 (IND)
Parameter Access Parameter value
Word 3 (PVA) (32 bit high word)
Parameter Access Parameter value
Word 4 (PVA) (32-bit low word/8-bit & 16-bit value)
See Parameter Message Request on page 6-4
Response on page 6-5 for a description of the data that is required in each
word.
Using Explicit Messaging
Request
11 10...0 15...12
SPM PNU
Subindex
(32-bit low word/8-bit & 16-bit value)
and Parameter Message
PowerFlex 20-COMM-P Profibus Adapter User Manual
6-3
Response
11 10...0
RC SPM PNU
Subindex
Parameter value
(32 bit high word)
Parameter value
Publication 20COMM-UM006B-EN-P