Instruction manual
• Read out holding register contents [03H]
Reads out the contents of the holding registers with the continuous
numbers for the specified quantity. The contents of holding register is
divided into the upper 8 bits and the lower 8 bits. They become the data
items in response message in the order of numbers.
(Example)
Reads out status signal, fault contents, data link status and frequency
reference from the VS-606V7 (slave 2).
* Twice as much as the number of reference message.
• Example of loop-back test [08H]
Command message is returned as a response message without being
changed. This function is used to check communication between the
master and the slave. Any arbitrary values can be used for test codes or data.
(Example) Loop-back test of slave 1 and VS-606V7
93
Slave address
Function code
Start
number
Quantity
CRC-16
Upper
Lower
Upper
Lower
Upper
Lower
02H
03H
00H
20H
00H
04H
45H
F0H
Slave address
Function code
Number of data*
CRC-16
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
02H
03H
08H
00H
65H
00H
00H
00H
00H
01H
F4H
AFH
82H
First
holding
register
Next
holding
register
Next
holding
register
Next
holding
register
Slave address
Function code
Error code
CRC-16
Upper
Lower
02H
83H
03H
F1H
31H
Reference message
(at normal operation)
Reference message
(at fault occurrence)
Response message
(at normal operation)
Slave address
Function code
Start
number
Quantity
CRC-16
Upper
Lower
Upper
Lower
Upper
Lower
01H
08H
00H
00H
A5H
37H
DAH
8DH
Slave address
Function code
Error code
CRC-16
Upper
Lower
01H
89H
01H
86H
50H
Slave address
Function code
Start
number
Quantity
CRC-16
Upper
Lower
Upper
Lower
Upper
Lower
01H
08H
00H
00H
A5H
37H
DAH
8DH
Reference message
(at normal operation)
Reference message
(at fault occurrence)
Response message
(at normal operation)
(For error code 03H, refer to page 99.)