Lumel ND20 - RS-485 INTERFACE; Register Communication Examples

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8. RS-485 INTERFACE
The implemented protocol is compliant with the PI-MBUS-300 Rev G,
Modicon. Parameter set of the serial ND20 meter link:
· identifier 0xBC
· meter address: 1..247
· baud rate 4.8, 9.6, 19.2, 38.4 kbit/s,
· working mode Modbus RTU,
· information unit 8N2, 8E1, 8O1, 8N1,
· maximum response time 600 ms.
· maximum quantity of read out registers in one request
41registers – 4 byte registers,
82 registers – 2 byte registers,
· implemented functions 03, 04, 06, 16, 17,
- 03, 04 - readout of registers,
- 06 - write of one register,
- 16 - write of n-registers,
- 17 - device identification,
Manufacturer’s settings: address 1, baud rate: 9600 baud, RTU 8N2
mode,
Device
address
Function Register
address
Number of
registers
CRC
Control sum
B1 B0 B1 B0
01 03 0F A0 00 02 C7 3D
Request:
Readout of n-registers (code 03h)
Example 1 .
Readout of 2 registers 16-bit of integer type, starting with
the register with the 0FA0h (4000) address - register values 10, 100.