Serial Communications Protocol Specifications - Swissvacuum.com
Serial Communications Protocol Specifications - Swissvacuum.com
Serial Communications Protocol Specifications - Swissvacuum.com
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INDEX<br />
INTRODUCTION...............................................................................................................................................................................4<br />
ERROR DETECTION.......................................................................................................................................................................5<br />
COMMUNICATION ERRORS .........................................................................................................................................................6<br />
IDENTIFICATION OF A DATA PACKET.........................................................................................................................................7<br />
MODBUS FUNCTIONS....................................................................................................................................................................8<br />
FIELDS DESCRIPTION ...................................................................................................................................................................9<br />
MODBUS FUNCTIONS DESCRIPTION .................................................................................................................................... 10<br />
READ MULTIPLE REGISTERS: FUNCTION CODE: 3 (DECIMALE)....................................................................... 11<br />
WRITING FUNCTION: FUNCTION CODE: 16 (DECIMAL) ......................................................................................... 12<br />
COMMUNICATION PARAMETERS............................................................................................................................................. 13<br />
CODE EXAMPLES......................................................................................................................................................................... 14<br />
C LANGUAGE .......................................................................................................................................................................... 15<br />
VISUAL BASIC.......................................................................................................................................................................... 17<br />
EXAMPLES OF READING AND WRITING QUERY.................................................................................................................. 18<br />
CALCULATED CRC TABLES...................................................................................................................................................... 24<br />
mICROPLC MEMORY LAYOUT VERS. 2.0 ............................................................................................................................... 25<br />
READING AREA............................................................................................................................................................................. 26<br />
PT100 MEASURES................................................................................................................................................................. 26<br />
ANALOGIC INPUTS MEASURES ......................................................................................................................................... 26<br />
CALCULATED INPUTS MEASURES................................................................................................................................... 26<br />
MESSAGES .............................................................................................................................................................................. 28<br />
USER AND REAL SETTINGS ............................................................................................................................................... 29<br />
SETPOINTS READING........................................................................................................................................................... 32<br />
TEST PROGRAM STATUS..................................................................................................................................................... 33<br />
WRITING AREA.............................................................................................................................................................................. 34<br />
NOTE ............................................................................................................................................................................................... 36<br />
APPENDIX A: CONNECTION OF A SERIAL CABLE ......................................................................................................... 37<br />
Figures<br />
Fig. 1 Master and Slave Pag. 3<br />
Fig. 2: Communication overview Pag. 4<br />
Fig. 3: Noise on the line Pag. 4<br />
Fig. 4: Decoding a data packet Pag. 5<br />
Fig. 5: Frame identification Pag. 7<br />
Fig. 6 CRC calculation Pag. 12<br />
Fig. 7: System logic layout Pag. 23<br />
Fig. 8: <strong>Serial</strong> cable Pag. 32<br />
<strong>Serial</strong> <strong>com</strong>munications protocol vers. 2.02 Angelantoni Industrie Spa Massa Martana (PG) Italy
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