Ebyte MA01-AXCX4020, User Manual

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Chengdu Ebyte Electronic Technology Co., Ltd.
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4DI+2DO
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MA01-AXCX4020 User Manual
Copyright ©2012–2023, Chengdu Ebyte Electronic Technology Co., Ltd.
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7.2 Instruction format (partial)
7.2.1 Read DO output coil status
Use 01 function code to read the output coil status, for example: read the status of two output coils
20 01 00 00 00 02 XX XX
Device ModBus
address
function code Register start address Number of output coils CRC check code
After sending the above command to the device via the 485 bus, the device will return the following values:
20 01 01 02 XX XX
Device ModBus
address
function code Number of bytes of data Status data returned CRC check code
The status data 02 returned above indicates that the output DO2 is on.
7.2.2 Read holding register
Use 03 function code to read one or more register values, for example: read DO1 working mode.
20 03 05 78 00 01 XX XX
Device ModBus
address
function code Register start address
Register read
quantity
CRC check code
After sending the above command to the device via the 485 bus, the device will return the following values:
20 03 02 00 00 XX XX
Device ModBus
address
function code Number of bytes of data Returned data CRC check code
The above 00 00 indicates that DO1 is in level mode.