modbus_write_bit - Man Page

write a single bit


int modbus_write_bit(modbus_t *ctx, int addr, int status);


The modbus_write_bit() function shall write the status of status at the address addr of the remote device. The value must be set to TRUE or FALSE.

The function uses the Modbus function code 0x05 (force single coil).

Return Value

The function shall return 1 if successful. Otherwise it shall return -1 and set errno.

See Also

modbus_read_bits(3) modbus_write_bits(3)


The libmodbus documentation was written by Stéphane Raimbault <>

Referenced By

libmodbus(7), modbus_read_bits(3), modbus_write_bits(3).

05/25/2023 libmodbus v3.1.7 libmodbus Manual