Single Bit Data Read/Write Commands (01 / 05) – Common for HMI

Function Code 01 Example – Single Bit Read

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This command does not reset the C02.Del.Total (Totalizer Clear) option. It is used for reading a single bit via HMI (01/05). When the 01 command is sent correctly, the slave responds by returning the requested bit status only.

Master Sends 01 (TX) Example

TX: 01 01 00 0A 00 01 A4 0E
  • Slave Address: 01 (Flow meter address)

  • Function Code: 01 (Read 1 bit)

  • Starting Address: 02 01 (C02.Del.Total memory address)

  • Quantity: 00 01 (Read 1 bit)

  • CRC: A4 0E (Error check)

Slave Response 01 (RX) Example

RX: 01 01 01 00 51 88
  • Slave Address: 01

  • Function Code: 01 (Read)

  • Data: 01 00 (Bit value, slave is online and responding)

  • CRC: 51 88

Function Code 05 Example – Single Bit Write (Trigger Totalizer Clear)

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This command activates the C02.Del.Total clear option, immediately resetting the totalizer to zero.

Master Sends (TX) Example

  • Slave Address: 01

  • Function Code: 05 (Write single register)

  • Starting Address: 02 01 (C02.Del.Total memory address)

  • Data: FF 00 (Trigger clear)

  • CRC: DC 42

Slave Response (RX) Example

  • Slave Address: 01

  • Function Code: 05

  • Starting Address: 02 01

  • Data: FF 00 (Echoes successful write)

  • CRC: DC 42

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