KVC KP390 - RS485 MODBUS Communication

22
KVC
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11-1-3-2 Alarm data setting command ( Command to read the setting point value )
11-1-3-3 Unit Request
11-1-3-4 Unit Change
11-2 RS485 MODBUS Communication
11-2-1 Communication specification
11-2-1-1 Communication method : RS485 2 Wire half duplex
11-2-1-2 Communication baud rate : 4800, 9600, 19200, 38400 bps ( Default : 38400 bps )
11-2-1-3 Data length : 8 Bit
11-2-1-4 Stop bit : 1 Bit
11-2-1-5 Parity : Even
11-2-1-6 Connected units : Max 32 units
11-2-1-7 Protocol : MODBus 1.1 RTU
11-2-2 FORMAT
11-2-2-1 Function code 3 ( 0x03 ) : Read holding registers
Request ( Master ----> Slave )
MENU COMMAND DATA RESPONSE DATA
SP1 value setting “11”
“d.dE±dd"
OK
SP2 value setting “12” “d.dE±dd" OK
0x01 0x03 0x00 0x00 0x00 0x16 xx xx
Address Command
Starting address No. of Data CRC 16
H byte L byte H byte L byte H byte L byte
MENU COMMAND DATA RESPONSE DATA
Unit request “20” “d”
"0" : Torr
"1" : Pa
MENU COMMAND DATA RESPONSE DATA
Unit Change “30” “d” OK
"0" : Torr
"1" : Pa