modbus_rtu_get_rts

Name

modbus_rtu_get_rts - get the current RTS mode in RTU

Synopsis
    int modbus_rtu_get_rts(modbus_t *ctx);

Description

The modbus_rtu_get_rts() function shall get the current Request To Send mode of the libmodbus context ctx. The possible returned values are:

    •   MODBUS_RTU_RTS_NONE

    •   MODBUS_RTU_RTS_UP

    •   MODBUS_RTU_RTS_DOWN

This function can only be used with a context using a RTU backend.

Return value

The function shall return the current RTS mode if successful. Otherwise it shall return -1 and set errno to one of the values defined below.

Errors

    •   EINVAL, the libmodbus backend is not RTU.

See also

    •   modbus_rtu_set_rts ⟨modbus_rtu_set_rts.md⟩