DC0-20mAUser Manual for Analog Data Acquisition Module

XY885-AII8

Brief introduction

Imported16Bit analog-to-digital conversion chip, convert8roadDC0-20mAsimulateThe signal is converted into a digital signal throughRS485Interface output,DC0-20mAEnter the corresponding numerical value as0-20000The highest measurable valueDC24mA.DC0-20mAAnalog signal input and working power supplyRS485Isolation between them.RS485Communication adopts standardsmodbus-rtuProtocol, compatible with various configuration software,PLCTouch screen networking. leave the factoryPresetsRS485Communication parameters: module address1, baud rate9600，8One data bit, no checksum,1Stop position, users can modify communication parameters through the upper computer parameter setting software.

2、 Main technical indicators

IIIRS485communication

3．1 RS485communication

Communication baud rate:2400、4800、9600、19200、38400、57600、115200, factory preset values9600；Parity bits: no parity, odd parity, even parity, factory default value without parity；8One data bit. standardmodbus-rtuProtocol, Instrument Address:1~247, factory preset values1Communication baud rate,The parity bit and communication address are set through the upper computer parameter setting software.

support03H、04HRead command,03H、04HThe function of reading commands is the same;06H、10HWrite commands.

Message format description:

command03H(perhaps04H): Read command

Host request: address+command+data address+Length+ CRCCheck Code

1byte + 1byte + 2byte + 2byte + 2byte

Address: For the module address to be queried, it can be found at1~247Internal settings, occupying 1One byte

Command:03H(perhaps04H)Read command, length is 1One byte

Data address: The starting address of the read data, occupying 2One byte

Data length: The length of the read data word

CRC16Verification code: Low8Located in the front, high8Located at the back, occupying2One byte

Module response:address+command+Length+Data information+ CRCCheck Code

1byte + 1byte + 1byte + nbyte + 2byte

Address: In response to the instrument address code, the length is 1One byte

Command:03H(perhaps04H)The length is 1One byte

Data length: The byte length of the read data

Data information: Read data

CRC16Verification code: occupied2One byte, low8Located in the front, high8Located at the back

3．2 Example of Communication Messages

Read data register(function code03H/04H): Read out8roadDC0-20mAMeasurement value,1~8The input values of the road current are2.000mA、4.000mA、4.505mA、8.756mA、10.337mA、12.000mA、15.006mA、20.000mAThe instrument address is1.

Host reads data frames(Data to16Binary format representation)：

Module responds to data frames(Data to16Binary format representation)：