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;