Honeywell RS-232, Reference Manual

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Message Exchange Formats
28 RS232 Communications Reference Manual 8/99
4.2 Read Contiguous 32-Bit Values
Introduction
Figure 4-1 shows the Read request and response format for Function Code 2 - Contiguous 32-Bit values.
This operation lets you read a list of 32-Bit values from a specific block given the starting index number
and the number of values involved.
Message Formats
Figure 4-1 Read Contiguous 32-Bit Request and Response Message Formats
Header
READ/WRITE
0 = Read
FUNCTION CODE
2 = Contiguous 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
Select from LCB Printout
INDEX NUMBER
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
02 = Contiguous 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
. . .