Unipulse F331, Operation Manual

Page: 51 / 88

42
7 OPTION
42
OP
TION
Chapter
7
03 (0x03) Read holding registers
Contents of slave holding registers are read.
No broadcast can be specified.
Specify the holding register start address and number of registers.
The slave transmits the contents of one register as expanded in double bytes.
* N = Number of registers
Example) Read the contents from HI limit (address 40002) to LO limit (address 40003).
Keep in mind that the relative address for reading the HI limit value is 0x01.
The example shows the case where the F331 settings are as follows:
04 (0x04) Read input registers
Contents of slave input registers are read.
No broadcast can be specified.
Specify the input register start address and number of registers.
The slave transmits the contents of one register as expanded in double bytes.
* N = Number of registers
[Request]
Function
1
byte
0x03
Start address
2
byte
s 0x0000 - 0xFFFF
Number of registers
2
byte
s 1 - 125 (0x7D)
[Response]
Function
1
byte
0x03
Number of data bytes
1
byte
2×N *
Register value
N×2
byte
s
[Error response]
Error code 1
byte
0x83 (fu 0x80)
Exception code 1
byte
01 or 02 or 03
[Request]
Function 03
[Response]
Function 03
Start address; higher 00 Number of data bytes 04
Start address; lower 01 HI limit; higher 00
Number of registers; higher 00 HI limit; lower 64
Number of registers; lower 02 LO limit; higher 00
LO limit; lower 32
HI limit
100 (0x0064)
LO limit
50 (0x0032)
[Request]
Function 1
byte
0x04
Start address 2
byte
s 0x0000 - 0xFFFF
Number of registers 2
byte
s 1 - 125 (0x7D)
[Response]
Function 1
byte
0x04
Number of data bytes 1
byte
2×N *
Register value N×2
byte
s
[Error response]
Error code 1
byte
0x84 (fu 0x80)
Exception code
1
byte
01 or 02 or 03