Moxa V2406-24I-CT-T-LX [54/81] Digital i o

V2406/2422/2426 Linux User’s Manual Programming Guide

4-4

Digital I/O

Digital Output channels can be set to high or low. The channels are controlled by the function call

set_dout_state( ). Use the digital input channels to detect the state change of the digital input signal. The DI

channels can also be used to detect whether or not the state of a digital signal changes during a fixed period

of time. This can be done with the function call set_din_event( ).

Return error code definitions:

#define DIO_ERROR_PORT -1 // no such port

#define DIO_ERROR_MODE -2 // no such mode or state

#define DIO_ERROR_CONTROL -3 // open or ioctl fail

#define DIO_ERROR_DURATION -4 // The value of duration is not 0

or not in the range,

40 <= duration <= 3600000 milliseconds (1 hour)

#define DIO_ERROR_DURATION_20MS -

5 // The value of duration must be a multiple of 20

#define DIO_OK 0

DIN and DOUT definitions:

#define DIO_HIGH 1

#define DIO_LOW 0

Moxa functions for DI/DO

Function int set_dout_state(int doport, int state)

Description Set the DOUT port to high or low state.

Input <doport> The DOUT port you want to set. Port starts from 0 to 3

<state> Set high or low state; DIO_HIGH (1) for high, DIO_LOW (0) for low.

Output None

Return refer to the error code

Function int get_din_state(int diport, int *state)

Description Get the DIN port state

Input <diport> The DIN port to get the state of. Port numbering is from 0 to 3

<state> Save the current state

Output <state> DIO_HIGH (1) for high, DIO_LOW (0) for low

Return Refer to the error code

Function int get_dout_state(int doport, int *state)

Description Get the DOUT port state

Input <doport> The DOUT port to get the state of.

<state> Save the current state.

Output <state> DIO_HIGH (1) for high, DIO_LOW (0) for low

Return Refer to the error code