Lebai Help

Modbus

After adding Modbus devices in the UI interface, you can communicate with Modbus devices

Set Timeout

lebai:set_modbus_timeout(device, timeout)
  • Parameters
    • device Device name
    • timeout Timeout duration in milliseconds (ms). Default 600ms

Set Timeout Retransmissions

lebai:set_modbus_retry(device, retry)
  • Parameters
    • device Device name
    • retry Number of timeout retransmissions. Default is 0.

Write Single Coil

lebai:write_single_coil(device, addr, value)
  • Parameters
    • device Device name
    • addr Register address
    • value Value to set

Write Multiple Coils

lebai:write_multiple_coils(device, addr, values)
  • Parameters
    • device Device name
    • addr Register address
    • values Values to set

Read Coils

values = lebai:read_coils(device, addr, num)
  • Parameters
    • device Device name
    • addr Register address
    • num Consecutive quantity

Read Discrete Inputs

values = lebai:read_discrete_inputs(device, addr, num)
  • Parameters
    • device Device name
    • addr Register address
    • num Consecutive quantity

Write Single Register

lebai:write_single_register(device, addr, value)
  • Parameters
    • device Device name
    • addr Register address
    • value Value to set

Write Multiple Registers

lebai:write_multiple_registers(device, addr, values)
  • Parameters
    • device Device name
    • addr Register address
    • values Values to set

Read Holding Registers

values = lebai:read_holding_registers(device, addr, num)
  • Parameters
    • device Device name
    • addr Register address
    • num Consecutive quantity

Read Input Registers

values = lebai:read_input_registers(device, addr, num)
  • Parameters
    • device Device name
    • addr Register address
    • num Consecutive quantity

Example

local device = "/dev/ttyS1"
lebai:set_serial_timeout(device, 200)
lebai:set_serial_baud_rate(device, 9600)

lebai:set_modbus_timeout("485_1", 500)
lebai:write_single_coil("485_1", "100", false)