Write One Bit - JUMO LOGOSCREEN nt Interface Description

4.6.3 Write one bit

Instruction
Response
Example
In the write bit function, the data blocks for instruction and response are
identical.
Slave Function
address 0x05
1 byte 1 byte
Slave Function
address 0x05
1 byte 1 byte
Writing a bit starting from bit address 0x0340 (this is bit 0 of the word address
0x0034).
For the addresses please refer to Chapter 7.2 Modbus addresses of important
device and process data, Page 47.
Instruction:
01 05 0340
Response (as instruction):
01 05 0340
4 Modbus protocol description
Bit address
2 byte
Bit address
2 byte
FF00 8DAA
FF00 8DAA
Bit value Checksum
xx00 CRC16
2 byte 2 byte
xx = 00  Bit is
set to 0
xx = FF  Bit is
set to 1
Bit value Checksum
CRC16
2 byte 2 byte
21