IT schedules next activation of the node

Syntax:

    IT := <real expression>;

This instruction is used to activate the node in which it appears after an interval time given by the current value of <real expression>. When executed, the value of <real expression> is assigned to the variable IT and an event is put in the future event list (FEL) with:

• The node number equal to the number in the NETWORK of the node being executed (this node number is not used by the programmer, who refers to the nodes by its names).
• An index equal to the current value of INO (1 for single nodes 1, 2, 3, .. for successive executions of a multiple node).
• Even parameter equal to the current value of EVP.
• Time equal to the current value of TIME + <real expression>, that is to say TIME + IT.

When the node is multiple, the instruction may be executed many times. In each execution an event is entered in the FEL. The successive values of the index are 1, 2, 3, .. etc.

See instruction NT (6.15) and procedure ACT (7.1).

The instruction can be used in any node, except of C type.

Examples:

1.      Ent (I) Lathe[INO] :: IT := UNIF(1.00, 1.03); SENDTO(Lathe[MIN]);
        Lathe (R) [1..4] ::

   Messages (parts) are generated each time the node Ent is activated. This happens at intervals taken at random from a uniform distribution between 1.00 and 1.03. The messages go to the less crowded of the four nodes Lathe.

2.       Signal (I) :: IF TIME < 1999
                        THEN IT := 1999 - TIME
                        ELSE WRITELN('This is the last signal');

   If the node is activated before the TIME = 1999, then an activation is scheduled for the time 1999 and then the message This is the last signal is written.
   

3.       Gate_n1 (G) [1..3] ::
           STATE BEGIN OPEN := NOT OPEN; IT := Interval[INO]; END;
           IF OPEN THEN SENDTO(Deposit[INO]);
         -----------------------------------------
         INIT
           ASSI Interval[1..3] = (17, 13, 19);

   Incoming messages are retained each in its gate while the gate is closed and allowed to passed to Deposit when the gate is open. The gates are alternatively closed and open. The intervals of each state OPEN and NOT OPEN are equal for a gate but are different for the different gates. For the first gate they are 17, for the second 13, for the third 19.

See examples 1, 6, 10, 13, 18 (GLIDER examples book).