At a Glance

This example covers canceling an exchange carried out with the OUT_IN_CHAR function.

When the exchange is launched, a unique number is assigned to it. This number remains valid until the end of the exchange.

The CANCEL function uses this number to interrupt the exchange to which it is assigned.

Programming the OUT_IN_CHAR Function

Programming in ST:

IF RE(%I0.3.8) AND NOT %MW170.0 THEN

   (* initialization of the data to send *)

   %MW173 := 10;

   (* communication function *)

   OUT_IN_CHAR(ADDR(‘{20.5}0.0.0.SYS’),1,Str_Out,Str_In,%MW170:4);

END_IF;

Programming the CANCEL Function

Programming in ST:

%MW180 := SHRZ_INT(%MW170,8);

IF RE(%I0.3.9) THEN

   CANCEL(%MW180,%MW185);

END_IF;

The CANCEL function comprises two parameters:

• on input: the exchange number to be cancelled

• on output: the report

It is necessary to initialize the first parameter with the number of the exchange to be cancelled. This number is located in the most significant byte of the first word of the management table. For us, this is the most significant byte of %MW170. Before sending the CANCEL function, it is necessary to create an 8 bit shift in order to recover the eight most significant bits of %MW170.

Request parameters: