Read out holding register contents [03h, Example of loop-back test [08h – IDEX Health & Science VS-606V7 Series User Manual
Page 96
96
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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