Instruction Manual

Rev 2.0 : X11CA-IM MASTER MODULE
6
EXAMPLE:
The following example reads registers 40108-40110 from the slave device 17.
11
HEX
= 10001
BIN
=17
DEC
6B
HEX
=1101011
BIN
=107
DEC
Field Name Example (Hex)
Slave Address 11
Function 03
Starting Address Hi 00
Starting Address L 6B
No. of Points Hi 00
No. of Points Lo 03
Error Check (LRC or CRC) --
Table 4-2 Modbus Function 3 Example-Query
Response
The register data in the response message is packed as two bytes per register, with
the binary contents right justified within each byte. For each register, the first byte
contains the high order bits and the second contains the low order bits.
EXAMPLE:
The following example is a response to the query.
Field Name Example (Hex)
Slave Address 11
Function 03
Byte Count 06
Data Hi (Register 40108) 02
Data Lo (Register 40108) 2B
Data Hi (Register 40109) 00
Data Lo (Register 40109) 00
Data Hi (Register 40110) 00
Data Lo (Register 40110) 64
Error Check (LRC or CRC) --
Table 4-3 Modbus Function 3 Example-Response
The register 40108 contains two byte values of 02 2B
HEX
(=555
DEC).
The register 40109 contains 00 00
HEX
(=0
DEC).
The register 40110 contains 00 64
HEX
(=100
DEC).