Mitsubishi Electric 800 Series Instruction Manual page 506

 Read Holding Register (reading of data of holding registers) (H03 or 03)
• Query message
a. Slave Address b. Function
(8 bits) H03
(8 bits)
• Normal response (Response message)
a. Slave Address b. Function
(8 bits) H03
(8 bits)
• Query message setting
Message
a Slave Address
b Function
c Starting Address
d No. of Points
• Content of normal response
Message
e Byte Count
f Data
 Example) Read the register values of 41004 (Pr.4) to 41006 (Pr.6) from slave address 17 (H11).
Query message
Slave Address Function
H11 H03
(8 bits) (8 bits)
Response message
Slave Address Function
H11 H03
(8 bits) (8 bits)
Read value
Register 41004 (Pr.4): H1770 (60.00 Hz)
Register 41005 (Pr.5): H0BB8 (30.00 Hz)
Register 41006 (Pr.6): H03E8 (10.00 Hz)
c. Starting Address
H L
(8 bits) (8 bits)
e. Byte Count
(8 bits) H
(8 bits)
Set the address to send messages to. Broadcast communication is not possible.
(Invalid when "0" is set.)
Set H03.
Set the address from which to start reading of data from the holding register.
Start address = start register address (decimal) - 40001
For example, when start register address 0001 is set, the data of holding register
address 40002 is read.
Set the number of holding registers to read. Data can be read from up to 125 registers.
The setting range is H02 to HFA (2 to 250).
Twice the number of reads specified by (d) is set.
The amount of data specified by (d) is set. Read data is output Hi bytes first followed by
Lo bytes, and is arranged as follows: data of start address, data of start address+1, data
of start address+2, and so forth.
Starting Address
H03 HEB H00
(8 bits) (8 bits) (8 bits)
Byte Count
H06 H17 H70
(8 bits) (8 bits) (8 bits)
d. No. of Points
H L
(8 bits) (8 bits)
f. Data
L ...
(n  16 bits)
(8 bits)
Description
Description
No. of Points
H03 H77
(8 bits) (8 bits)
Data
H0B HB8 H03 HE8
(8 bits) (8 bits) (8 bits) (8 bits)
5.12 (N) Operation via communication and its settings
CRC Check
L H
(8 bits) (8 bits)
CRC Check
L H
(8 bits) (8 bits)
CRC Check
H2B
(8 bits)
CRC Check
H2C HE6
(8 bits) (8 bits)
5. PARAMETERS
3
4
5
5
5
6
7
8
9
10
505