VIPA CPU 314ST - Page 190

Command telegram
Slave address Function code Address 1. bit Number of bits Check sum
CRC/LRC
1byte 1byte 1word 1word 1word
Respond telegram
Slave
address
Function
code
Number of
read bytes
Data 1.
byte
Data 2.
byte
... Check sum
CRC/LRC
1byte 1byte 1byte 1byte 1byte 1word
max. 250byte
03h: Read n words of master output area 4x
04h: Read n words master input area 3x
Command telegram
Slave address Function code Address 1. bit Number of
words
Check sum
CRC/LRC
1byte 1byte 1word 1word 1word
Respond telegram
Slave
address
Function
code
Number of
read bytes
Data 1.
word
Data 2.
word
... Check sum
CRC/LRC
1byte 1byte 1byte 1word 1word 1word
max. 125words
Code 05h: Write 1 bit to master output area 0x
A status change is via "Status bit" with following values:
"Status bit" = 0000h ® Bit = 0
"Status bit" = FF00h ® Bit = 1
Command telegram
Slave address Function code Address bit Status bit Check sum
CRC/LRC
1byte 1byte 1word 1word 1word
Read n words 03h, 04h
Write 1 bit 05h
VIPA System 300SDeployment PtP communication
Modbus - Function codes
HB140 | CPU | 314-6CF03 | GB | 16-43 190