Read N Words - JUMO LOGOSCREEN nt Interface Description

4 Modbus protocol description

4.6.2 Read n words

Data request
Response
Example
20
This function is used to read n words starting from a specific address.
Slave Function
address 0x03 or 0x04
1 byte 1 byte
Slave Function
address 0x03 or 0x04
1 byte 1 byte
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:
01 03 1257
Response:
01 03 0C 1999
Measured
value 1
200,1
Address
first word
2 byte
Number of
byte read
1 byte
0006 7160
4348 4CCC 4348
Measured
value 2
200,3
Number Checksum
of CRC16
words
2 byte 2 byte
Word Checksum
value(s) CRC16
x byte 2 byte
2666 4396
Measured
value 3
300,3
8548