Sending messages with conditional delimiters

When WSim processes a conditional delimiter after a message was generated or an AID byte was set, it interrupts message generation and sends the message in the buffer. When all conditions for message generation were satisfied, the device reenters message generation, and WSim continues processing the message generation deck. In contrast to unconditional delimiters, conditional delimiters act as delimiters only when a message exists in the buffer.

The following statements act as conditional delimiters:

TEXT	Interrupts message generation and sends the message in the buffer to the system under test. When the device reenters message generation,WSim places a new message into the buffer.
CMND	Interrupts message generation and sends the message in the buffer to the system under test. When the device reenters message generation,WSim places an SNA command into the buffer. The CMND statement is valid during SNA simulations only.
ENDTXT	Interrupts message generation, sends the message in the buffer to the system under test, and ends message generation for a particular device.

Note: If a message is generated by a TEXT statement and the cursor is moved with a cursor movement statement such as TAB, the next TEXT statement encountered by WSim does not act as a delimiter. Also, coding MORE=YES on the previous TEXT statement causes the current TEXT statement not to act as a delimiter.

As shown in the following example, a TEXT statement generates a message in the buffer at the current cursor location.

DECK1  MSGTXT
*                      Beginning of DECK1.
MSG1   TEXT  ($DATE$)  Places the current date into the buffer.
       ENDTXT          End of DECK1.

To send the message from the buffer to the system under test, you must code a delimiter. However, as discussed in How delimiters are classified, the preceding example already contains a conditional delimiter, the ENDTXT statement. When WSim processes MSG1, it places the current date into the buffer. Then WSim processes the ENDTXT statement, which indicates that WSim has reached the end of DECK1. Message generation is stopped at the ENDTXT statement, and MSG1 is sent to the system under test.

When you create message generation decks that are more complex than DECK1, do not use the ENDTXT statement as the only delimiter in the deck. If you code a deck with the ENDTXT statement as the only delimiter,WSim can enter an infinite processing loop within the message generation deck. Instead, you can use a second TEXT statement to send the message generated by the first TEXT statement. As a conditional delimiter, the second TEXT statement sends the message generated by the preceding TEXT statement.

The following example illustrates a series of TEXT statements serving as conditional delimiters:

DECK1  MSGTXT
*                        Beginning of DECK1.
MSG1   TEXT  ($DATE$)    Places the current date into the buffer.
MSG2   TEXT  (PW3)       Sends the current date to the system under test and
*                        ends this pass though message generation.  When
*                        WSim reenters message generation, it places PW3
*                        into the buffer.
MSG3   TEXT  (USER3)     Sends PW3 to the system under test and ends this
*                        pass through message generation.  When WSim
*                        reenters message generation, it places USER3
*                        into the buffer.
       ENDTXT            Sends USER3 to the system under test and specifies
*                        the end of DECK1.

Steps:

In the preceding example, WSim places MSG1 into the buffer and continues to process the message generation deck. When WSim processes MSG2, however, MSG2 acts as a delimiter and interrupts message generation. This pass through message generation ends, and WSim sends MSG1 to the system under test.
When all conditions for message generation were met, the device reenters message generation.WSim then places MSG2 into the buffer. For a list of conditions required for message generation, see How delimiters affect the message generation process.
In turn, MSG3 interrupts message generation until all required conditions were met. This pass through message generation ends, and WSim sends MSG2 to the system under test. When the device enters message generation again, WSim places MSG3 into the buffer.
Because MSG3 is in the buffer when WSim processes the ENDTXT statement, the ENDTXT statement serves as a delimiter.WSim stops message generation for DECK1 and sends MSG3 to the system under test.