Mitsubishi Electric 800 Series Instruction Manual page 578

Read Holding Register access Log (H46 or 70)
• Queries by function codes H03 and H10 are supported.
The number and start address of holding registers successfully accessed by the previous communication are returned.
"0" is returned for both the number and start address for queries other than the function codes.
• Query message
a. Slave b.
Address Function
H46
(8 bits)
(8 bits)
• Normal response (Response message)
a. Slave b.
Address Function
H46
(8 bits)
(8 bits)
• Query message setting
Message
a Slave Address
b Function
• Content of normal response
Message
c Starting Address
d No. of Points
Example) Read the successful register start address and number of successful accesses from slave address 25 (H19).
Query message
Slave
Function
Address
H19 H46
(8 bits) (8 bits)
Normal response (Response message)
Slave
Function
Address
H19 H10
(8 bits) (8 bits)
Two successful reads of start address 41007 (Pr.7) are returned.
(N) Operation via communication and its settings
CRC Check
L H
(8 bits) (8 bits)
c. Starting
d. No. of Points
Address
H L H
(8 bits) (8 bits) (8 bits)
Set the address to send messages to. Broadcast communication is not possible.
(Invalid when "0" is set.)
Set H46.
The start address of the holding register that was successfully accessed is
returned.
Start address = start register address (decimal) - 40001
For example, when start address 0001 is returned, the holding register address
that was successfully accessed is 40002.
The number of holding registers that were successfully accessed is returned.
CRC Check
H8B HD2
(8 bits) (8 bits)
Starting
No. of Points
Address
H03 HEE H00
(8 bits) (8 bits) (8 bits)
CRC Check
L L H
(8 bits) (8 bits) (8 bits)
Description
Description
CRC Check
H02 H22 H61
(8 bits) (8 bits) (8 bits)
577
PARAMETERS
5
GROUP
N