Allen-Bradley PowerFlex 20-COMM-P FRN 1 Series User Manual page 76

6-6 Using Explicit Messaging (Parameter Protocol)
Parameter Protocol Examples
Read Examples
Figure 6.3 Overview Parameter Message Format (Read Request)
Bit 15-12
Parameter Access
Word 1 (PCA)
Parameter Access
Word 2 (IND)
Parameter Access
Word 3 (PVA)
Parameter Access
Word 4 (PVA)
Request
RC
Set to "1" ('0001') binary to read
SPM
Not used
PNU
Parameter number to read
Subindex
Selects which DPI port to talk to ("0" = DPI
Host, "5" =20-COMM-P on PowerFlex 70
Request
11
RC SPM PNU
Subindex
Not Used
Not Used
Not Used
Not Used
10-0 15-12
RC
Response
RC
"1" ('0001') Transferring 8-bit or 16-bit
parameter value
"2" ('0010') Transferring a 32-bit
parameter value
"7" ('0111') Request rejected (including fault
code)
SPM
Not used
PNU
Confirms the Parameter number (if
successful, equals the PNU from the
request)
Subindex
Confirms the DPI port (if successful, equals
the Subindex from the request)
Parameter value high word
Contains a "0" if returning a value from a
16-bit parameter and the high word from a
32-bit parameter
Parameter value low word
Contains the value from a 8-bit or 16-bit
parameter, the low word if reading from a
32-bit parameter, or the fault code (if RC =
"7")
Response
11
SPM PNU
Subindex
Parameter value high
(32 bit high word)
Parameter value low
(32-bit low word/ or
8-bit/16-bit value)
10-0