Instruction Manual

96
• 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 transmission 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
Reference message
(at normal operation)
(For error code 03H, refer to
page 99.)
Response message
(at normal operation)
Reference message
(at fault occurrence)
Slave address 02H
Function code 03H
Start
number
Upper 00H
Lower 20H
Quantity
Upper 00H
Lower 04H
CRC-16
Upper 45H
Lower F0H
Slave address 02H
Function code 03H
Number of data* 08H
First
holding
resistor
Upper 00H
Lower 65H
Next
holding
resistor
Upper 00H
Lower 00H
Next
holding
resistor
Upper 00H
Lower 00H
Next
holding
resistor
Upper 1H
Lower F4H
CRC-16
Upper AFH
Lower 82H
Slave address 02H
Function code 83H
Error code 03H
CRC-16
Upper F1H
Lower 31H
Reference message
(at normal operation)
Response message
(at normal operation)
Reference message
(at fault occurrence)
Slave address 01H
Function code 08H
Start
number
Upper 00H
Lower 00H
Quantity
Upper A5H
Lower 37H
CRC-16
Upper DAH
Lower 8DH
Slave address 01H
Function code 08H
Start
number
Upper 00H
Lower 00H
Quantity
Upper A5H
Lower 37H
CRC-16
Upper DAH
Lower 8DH
Slave address 01H
Function code 89H
Error code 01H
CRC-16
Upper 86H
Lower 50H