stopping the MultiProcessor

Hi,

-i wanted to use the multiprocessor to represent a service box of a medical facility, so i can have different process/operators for different patients. One of the things that i have to do is stop the multiprocessor when a patient is waiting for an exam result and resume operation when the exam is ready. The thing is, i cant stop the multiprocessor using stopobject function through a message on the process finish, i'm not sure if i'm doing something wrong.

-i did a small example model of the problem in wich i send a message from the multiprocessor to a queue and on that message stop the multiprocessor. if i sent it as an instant message i get a weird behavior of the multiprocessor, but if i send it delayed it works as i first though it should work, just wanted to know why the different results...

-the top multiprocessor is sending the message instantly, and the bottom one is sending a delayed message 0.01 time units later..i was resumming operation through the script windows (var1 for the top multiprocessor, var2 for the bottom one)


thanks in advance

Pablo Concha E.

Pablo,
Your example illustrates the difference between the senddelayedmessage command and the sendmessage command. The pick option you used contains an 'if' statement that decides whether to use the senddelayedmessage command (if delay time is positive or 0) or a sendmessage command (when a -1 or any negative number is passed in as the delay time). The difference between these two commands is that a sendmessage command is sent out right at that instance in your code; it won't have any knowledge of the code that is to be executed after it. Whereas a senddelayedmessage command is sent after all the code and related events have taken place. Hope this helps. There is a difference between sending at -1 and sending at 0.

Brenton,
Thanks for the explanation, i had not realized the difference between the commands,

regards,

Pablo Concha E.

This is interesting. I never realized that there is a -1 parameter value for senddelayedmessage() and there is a difference between sendmessage() and senddelaymessge() with 0 as the delayed time. This should be documented better in the Flexsim command help. Wierd problems may occur if you are not aware of the difference.

Alan you are right that there is weak command documentation for the differences between using a senddelayedmessage() with a delaytime of 0 and using the sendmessage() command, so let me try to explain things a little further...


First of all, there is no -1 parameter for the senddelayedmessage(). The -1 is a value you can pass into one of the picklist options for a trigger field to invoke something special - let me explain.

It's important to note that there are two commands avalaible in Flexsim for sending messages: sendmessage() and senddelayedmessage(). The first command sends a message immediately so it is more like calling a subroutine. The second command creates an event to send a message at a later time. If the "later time" is 0 seconds, then it will send the message at the same simulation time as now, but the message won't be sent until all pending events associated with the current simulation time have finished.

Now, if you look at the code for the picklist option named "Send Message" that is found in a lot of the trigger fields, you will see that in order to accomodate both types of messaging schemes using a single picklist option, we use a conditional statement that simply says if the number typed into the picklist template for the "Delay Time: " is a number less than 0, then call the sendmessage() command as opposed to the senddelayedmessage() command.

I'm afraid we've introduced some confusion by trying to put two entirely different commands into a single picklist option. Because of this confusion, I rarely use the Send Message picklist option, and usually choose to just type in either the sendmessage or senddelayedmessage command depending on which one I want to use!

Let me throw out one more bit of information that's related to this. If you're building your own task sequences and you want to use the TASKTYPE_SENDMESSAGE, you will run into similar confusion. Once again the confusion comes due to the fact that we only have one task type for sending messages, and yet we wanted to give the user the ability to send an immediate message or create an event to send a delayed message. To accomplish this, we use var4 of the inserttask command. By default a message will be sent immediately if var4 is not specified or is 0. If var4 is a -1 a delayed message will be sent in 0 time, and if var4 is a value greater than 0, a delayed message will be sent in that many time units. As you can see, this is opposite from the way the "Send Message" picklist option was set up. I think we will redesign the picklist option in a future release in order to avoid mistakes.

Now to really screw with you, I need to warn you that there is currently a bug in v4.01 that keeps var4 of the inserttask command from even being passed properly in flexscript (it works fine in C++ however). This will be fixed in the next release.