Mitsubishi Electric FR-F820-00046, Instruction Manual

Page: 665 / 940

Parameters (N) Operation via communication and its settings
FR-F800 5 - 493
Read holding register (reading of data of holding registers) (H03 or 03)
●
Query message
●
Normal response (Response message)
●
Query message setting
●
Content of normal response
Slave address Function Starting address No. of points CRC check
(8 bits)
H03
(8 bits)
H
(8 bits)
L
(8 bits)
H
(8 bits)
L
(8 bits)
L
(8 bits)
H
(8 bits)
Slave address Function Byte count Data CRC check
(8 bits)
H03
(8 bits)
(8 bits)
H
(8 bits)
L
(8 bits)
...
(n × 16 bits)
L
(8 bits)
H
(8 bits)
Message Description
Slave address
Set the address to send messages to. Broadcast communication is not possible.
(Invalid when "0" is set.)
Function Set H03.
Starting address
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.
No. of points Set the number of holding registers to read. Data can be read from up to 125 registers.
Tab. 5-244: Description of the query message
Message Description
Byte count
The setting range is H02 to HFA (2 to 250).
Twice the number of reads specified by
is set.
Data
The amount of data specified by 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 a 1, data of start
a 2, and so forth.
Tab. 5-245: Description of normal response
Example Read the register values of 41004 (Pr. 4) to 41006 (Pr. 6) from slave address 17 (H11).
Query message
Response message
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)
Slave address Function Starting address No. of points CRC check
H11
(8 bits)
H03
(8 bits)
H03
(8 bits)
HEB
(8 bits)
H00
(8 bits)
H03
(8 bits)
H77
(8 bits)
H2B
(8 bits)
Slave address Function Byte count Data CRC check
H11
(8 bits)
H03
(8 bits)
H06
(8 bits)
H17
(8 bits)
H70
(8 bits)
H0B
(8 bits)
HB8
(8 bits)
H03
(8 bits)
HE8
(8 bits)
H2C
(8 bits)
HE6
(8 bits)