Honeywell RS-232, Reference Manual

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Message Exchange Formats
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4.3 Read Scattered 32-Bit Values
Introduction
Figure 4-2 shows the Read request and response format for Function Code 3 - Scattered 32-Bit values. This
operation lets you read 32-Bit values from a specific block given the index numbers and the number of
values involved.
Message Formats
Figure 4-2 Read Scattered 32-Bit Request and Response Message Formats
Header
READ/WRITE
0 = Read
FUNCTION CODE
3 = Scattered 32 Bit Values
NUMBER OF VALUES REQUESTED
FILLER BYTE:
For Word Alignment
TABLE FIELD*
1 = Function Block Configuration Parameters (Static)
2 = Function Block I/O Parameters (Dynamic)
BLOCK NUMBER(Note 1)
Select from LCB Printout.
INDEX NUMBER(Note 1)
Index number of the desired
parameter within the selected block
See Parameter Index tables for
Block types in Section 5.
* Configuration Parameters(static) and
I/O parameters(dynamic) cannot be accessed
in the same message since both the Static parameters
and the Dynamic parameters each start at Index Number 0.
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
0
Request Message
Response Message
Data Data Data Data
DATA FIELD
Four Bytes of data (32-bit IEEE Floating Point)
for each value returned (See Subsection 4.6)
ACKNOWLEDGE/
UNACKNOWLEDGE
09 = Acknowledge
0a = Unacknowledge
FUNCTION CODE
03 = Scattered 32 Bit Values
(If response is Unacknowledge, then an error code is
returned instead of a function code. See Table 2-1.)
NUMBER OF VALUES RETURNED
. . .
Note 1. One set of Block and Index for each value requested