ND30PNET-09 -
User's Manual
32
8 SERIAL INTERFACES
8.1 RS485 INTERFACE – the list of parameters
The implemented protocol is in accordance with the PI-MBUS-300 Rev G standard of Modicon
Company. The list of serial link parameters of ND30PNET meter:
ID
0xE0,
meter address
1..247,
baud rate 4.8, 9.6, 19.2, 38.4, 57.6, 115.2 kbit/s,
operation mode
Modbus RTU,
information unit
8N2, 8E1, 8O1, 8N1,
maximum time to commence the response
600 ms,
maximum number of read registers in one query
- 61 registers
– 4 byte,
- 122 registers
– 2 byte,
implemented functions
-03, 04, 06, 16, 17,
- 03, 04 registers reading,
- 06 saving one register,
- 16 saving n - registers,
- 17 identification of the device,
Default settings: address 1, baud rate 9.6 kbit/s, mode RTU 8N2.
8.2 Examples of registers reading and saving
Readout of n-registers (code 03h)
Example 1 .
Readout of 2 registers 16-bytes of integer type, starting with the register addressed
0FA0h (4000) - registers values 10, 100.
Request:
Address of
the device
Function
Address of the register
Number of registers
Checksum
CRC
B1
B0
B1
B0
01
03
0F
A0
00
02
C7 3D
Response:
Address of
the device
Function
Number
of bytes
Value from register
0FA0 (4000)
Value from register
0FA1 (4001)
Checksum
CRC
B1
B0
B1
B0
01
03
04
00
0A
00
64
E4 6F
Example 2 .
Readout of 2 registers 32-byte of float type as a combination of 2 registers 16-byte
starting with the register addressed 1B58h (7000) - registers values 10, 100.
