I/O signal reference method

The invention provides a reference method of an I/O signal. The reference method comprises the following steps: S1, an identifier of a referenceable I/O signal is defined; s2, the application module locally creates a variable object corresponding to the identifier of the reference I/O signal by referring to the identifier of the I/O signal, and adds the variable object into a mapping table in which the identifier of the I/O signal is in one-to-one correspondence with the variable object; s3, an access mapping relationship is established between the variable object and the I/O signal through aninternal communication mechanism according to the mapping table; s4, the application module controls and accesses the I/O signal by reading and writing the variable object. In the method, the external I/O signals are controlled and accessed by operating the local variable object when the application module runs, program architecture is decoupled in a layered mode, and the method has the advantages that I/O access is flex