Siemens SENTRON PAC3100 - Character Frame; A.2.2 Character Frame

Appendix
A.2 Modbus RTU
SENTRON PAC3100
126 Manual, 07/2009, A5E02385159B-01
A.2.2 Character frame
The MODBUS RTU specification defines the data format. The user can change the data
format.
Structure of the character frame
The data is transferred between the SENTRON PAC Power Monitoring Device and the
MODBUS master via the serial interface in an 11-bit character frame. In exceptional cases,
only 10 bits are used.
GDWDELWVVWDUWELWGDWDELWVSDULW\ELWVWRSELW
6LJQDOVWDWXV
6LJQDOVWDWXV
6LJQDOVWDWXV
6LJQDOVWDWXV
GDWDELWVVWDUWELWGDWDELWVVWRSELWV
VWDUWELW
SDULW\ELW
GDWDELWV
VWRSELW
VWDUWELW
GDWDELWV
VWRSELWV

  
  

  
  
Figure A-1 11-bit character frame
6LJQDOVWDWXV
6LJQDOVWDWXV
GDWDELWVVWDUWELWGDWDELWVVWRSELW
VWDUWELW
GDWDELWV
VWRSELW

  
 
Figure A-2 10-bit character frame
The least significant bit (LSB) is sent at the start of the eight data bits, and the most
significant bit (MSB) is sent at the end.