Code
Command
Description
01h
Read n bits
Read n bits of master output area 0x
02h
Read n bits
Read n bits of master input area 1x
03h
Read n words
Read n words of master output area 4x
04h
Read n words
Read n words master input area 3x
05h
Write 1 bit
Write 1 bit to master output area 0x
06h
Write 1 word
Write 1 word to master output area 4x
0Fh
Write n bits
Write n bits to master output area 0x
10h
Write n words
Write n words to master output area 4x
Point of View of "Input" and "Output" data
The description always takes place from the point of view of the master. Here data, which
were sent from master to slave, up to their target are designated as "output" data (OUT)
and contrary slave data received by the master were designated as "input" data (IN).
If the slave announces an error, the function code is send back with an "ORed" 80h.
Without an error, the function code is sent back.
Slave answer:
Function code OR 80h
®
Error
Function code
®
OK
1 word
High-byte Low-byte
The shown check sums CRC at RTU and LRC at ASCII mode are automatically added to
every telegram. They are not shown in the data block.
Code 01h: Read n bits of master output area 0x
Code 02h: Read n bits of master input area 1x
Respond of the slave
Byte sequence in a word
Check sum CRC, RTU,
LRC
Read n bits 01h, 02h
System 300S
+
Deployment PtP communication
Modbus - Function codes
HB140 | CPU | 315-4PN23 | en | 18-02
85
