Function Code - Teledyne 7500 Instruction Manual

5.4 Function code

According to MODBUS protocol, register numbers are assigned by function codes.
Each function code acts on specific register number.
This correspondence is shown in Table 5-2, and the message length by function is shown in
Table 5-3.
Table 5-2 Correspondence between function codes and objective address.
Function code
No. Function
03 Read out
H
(continuously)
04 Read out
H
(continuously)
06 Write-in
H
10 Write-in
H
(continuously)
Table 5-3: Function code and message length
Function Contents
code
03 Read-out of
H
word data
04 Read-out of
H
word data
(read-out
only)
06 Write-in of
H
word data
10 Write-in of
H
continuous
word data

Object
Holding
register
Input register
Holding
register
Holding
register
Number of Command message
designatable
Minimum
data
60 words 8
15 words 8
1 word 8
60 words 11
11
Teledyne Analytical Instruments
Resister No.
No. Contents
4xxxx Read out / Write in
word data
3xxxx Read out word
4xxxx Read out / Write in
word data
4xxxx Read out / Write in
word data
[Unit: byte]
Response message
Maximum Minimum Maximum
8 7
8 7
8 8
137 8
data
133
133
8
8