JUMO LOGOSCREEN nt - Header Functionality Overview

4 Modbus protocol description
20
4.6.2 Read n words
This function is used to read n words starting from a specific address.
Data request
Response
Example Reading the first 3 analog inputs (these are the first 6 words starting from
Modbus address 0x1257).
For the analog input address please refer to Chapter 7.2 Modbus addresses of
important device and process data, Page 47.
Data request:
Response:
Slave
address
Function
0x03 or 0x04
Address
first word
Number
of
words
Checksum
CRC16
1 byte 1 byte 2 byte 2 byte 2 byte
Slave
address
Function
0x03 or 0x04
Number of
byte read
Word
value(s)
Checksum
CRC16
1 byte 1 byte 1 byte x byte 2 byte
01 03 1257 0006 7160
01 03 0C 1999 4348 4CCC 4348 2666 4396 8548
Measured
value 1
200,1
Measured
value 2
200,3
Measured
value 3
300,3