Serial Communications Protocol Specifications - Swissvacuum.com

067: 049 0031 error check
> 068: 068 0044 error check
� End packet.
> Data received: (idx) (dec) (hex)
> 000: 017 (0011) mplc address
> 001: 016 (0010) modbus function number
> 002: 008 (0008) high order address
> 003: 252 (00FC) low order address
> 004: 000 (0000) quantity
> 005: 030 (001E) quantity
> 006: 128 (0080) error check
> 007: 193 (00C1) error check
> End packet.
READING OPERATION
- 20 -
Let’ s say that the following data are returned from the slave to the master:
Temperature: 137.6 Celsius degree
Rel. Humidity: 0.0%
Temperature channel: ON
Rel. Humidity channel: ON
Run bit: ON
Dedicated contacts: ON
In the example below we read 104 registers, starting at address 2000. Please note that many of the data returned by
the controller are not used, so it is also possible to read just a sub-block of these registers, containing only the data
we really need to know.
See the controller memory map to know more about the reading area.
> Query sent:
> 000: 017 0011 mplc address
> 001: 003 0003 modbus function number
> 002: 007 0007 memory address high
> 003: 208 00D0 memory address low
> 004: 000 0000 number of registers high
> 005: 104 0068 number of registers low
> 006: 070 0046 error check
> 007: 057 0039 error check
� End packet.
> Data received: (idx) (dec) (hex)
> 000: 017 (0011) mplc address
> 001: 003 (0003) modbus function number
> 002: 208 (00D0) byte count
> 003: 053 (0035) mplc addr. 2000 (h.o. data) [ pt100 sensors ]
> 004: 189 (00BD)
> 005: 000 (0000) mplc addr. 2001 (h.o. data)
> 006: 000 (0000)
> 007: 058 (003A) mplc addr. 2002 (h.o. data)
> 008: 243 (00F3)
> 009: 000 (0000) mplc addr. 2003 (h.o. data)
> 010: 000 (0000)
> 011: 000 (0000) mplc addr. 2004 (h.o. data)
Serial communications protocol vers. 2.02 Angelantoni Industrie Spa Massa Martana (PG) Italy