chStatus (Function)

The "chStatus()" function will return the status of the specified channel.

If the specified channel has been initialized, the chStatus() function will return the current number of messages.

Input:

ch : CHANNEL

The channel to query.

Returns: INT

Declaration:

FUNCTION chStatus : INT;
VAR_INPUT
   ch : CHANNEL;
END_VAR;

Example:

THREAD_BLOCK Thread;
VAR_INPUT
   ch : CHANNEL;
   id : SINT;
   ...
END_VAR;
VAR
   buf : ARRAY[1..30] OF SINT;
   len : INT;
   ...
END_VAR;
   ...
   // Do while channel initialized
   WHILE chStatus(ch:=ch) > -1 DO
      // peek at data
      len := chPeek(ch:=ch,msg:=ADDR(buf),lenmax:=SIZEOF(buf));
      IF len > 0 THEN
         // Is package sent to me?
         IF buf[1] = id THEN
            // Read data
            chRead(ch:=ch,msg:=ADDR(buf),lenmax:=SIZEOF(buf));
            // Act on data
            ...
         END_IF;
      END_IF;
      ...
   END_WHILE;
END_THREAD_BLOCK;