Chengdi RS485 Pressure Gague Wiring Definition and MODBUS Protocol
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485CommunicationPressureGague MODBUSProtocolAndWiringInstructions Brown12~24VDCBlue :0V White 485A D+ Orange 485B D-BlackDigitalswitchingoutput Data CRC Address Funtion DataFormat 8bit 8bit n*2*8 bit 16bit SingleFrame Thedefaultbaudrateis19200,with1startbit,8databits,1stopbits,andnoparitybit. TheaddressofPressureGaguecanbeadjustedfrom1to247,withadefaultvalueof01(hexadecimal01H). Format FunctionCode RegisterAddressDescription: Address Corresponding PressureSwitch Ontologysettings Normallyopenand normallyclosed settingvalue Displayvalue ne-tuningsettings Microvalue shieldingfunction - 1013~1000 NC correspondingto - 101.3kPa~100kPa 0~1 Correspondingto Switchingoutput OUT1targetvalue correspondingto correspondingto upperlimitvalue out1_down_value~1.000MP out1_down_value~101.0kPa OUT1targetvalue correspondingto correspondingto lowerlimitvalue - 0.100MPa~out1_up_value - 101.0kPa~out1_up_value EASY,HYS,WCMP 0~3 Correspondingto R_ON,G_ON,RED,GREEN EASY,HYS,WCMP 0~3 Correspondingto R_ON,G_ON,RED,GREEN Read /write UNIT no.nc

03HCommandExample Hostsend DriveAddress FunctionCode High-order Low-order High-order Low-order Low-order High-order Pressureswitchreturn DriveAddress 01H FunctionCode 03H DataQuantity 04H High-order 00H Data1 Low-order 00H High-order 00H Data2 Low-order 00H Low-order FAH CRC High-order 33H High-order Low-order High-order Low-order Low-order High-order Pressureswitchreturn DriveAddress 01H FunctionCode 04H DataQuantity 02H High-order 00H Data1 Low-order 00H Low-order B9H CRC High-order 30H High-order Low-order High-order Low-order Low-order High-order Pressureswitchreturn DriveAddress 01H...