Ventana software support forum

Greetings!
I need to couple Vensim and SAS. Since SAS only acts as a client I tried to call Vensim directly from SAS via DDE. For some reason, Vensim does not respond to the comments that I pass to it. There is no error message from SAS. It looks like it does its job of passing the commands. The lines of code I use and the log from SAS are below this note. Could you help me getting this work? This is supposed to be very straightforward; either I am missing a simple point or maybe Vensim is not compatible with SAS?

Thank you in advance,

options noxwait noxsync;
x '"C:\Program Files\Vensim\Vensimdp.exe"';
filename tst dde 'vensim|system';
data _null_;
file tst;
put '[SPECIAL>LOADMODEL|C:\Intro.vmf]';
put '[SIMULATE>RUNNAME|C:\bob1]';
put '[MENU>RUN|O]';
put '[MENU>EXIT]';
run;

The log:
22 options noxwait noxsync;

23 x '"C:\Program Files\Vensim\Vensim.exe"'

23 ! ;

24 data _nll_;

25 x=sleep(10);

26 run;



NOTE: The data set WORK._NLL_ has 1 observations and 1 variables.

NOTE: DATA statement used (Total process time):

real time 10.01 seconds

cpu time 0.03 seconds


27 filename tsst dde 'vensim|system' command;

28 data _null_;

29 file tsst;

30 put '[SPECIAL>LOADMODEL|C:\Intro.vmf]';

31 run;



NOTE: The file TSST is:

DDE Session,

SESSION=vensim|system,RECFM=V,LRECL=256



NOTE: 1 record was written to the file TSST.

The minimum record length was 32.

The maximum record length was 32.

NOTE: DATA statement used (Total process time):

real time 0.01 seconds

cpu time 0.01 seconds

There is no reason why it should not work as long as SAS is passing the DDE commands correctly.

The line
x '"C:\Program Files\Vensim\Vensimdp.exe"';

Does that run Vensim? If so, try starting Vensim before executing the SAS code. Maybe the code runs before Vensim has started up properly.

Tony.

I also notice there is s vensimdp.exe in one place and a vensim.exe with no dp in another and that may be a source of confusion.

Generally DDE is not very reliable so if you can reconfigure your application to call the Vensim DLL that may work better.

Thanks for the replies... Unfortunately, before posting my inquiry, I had already made sure that Vensim started properly before executing the rest of the code. I had also tried running vensim.exe instead of vensimdp.exe. So none of them can be the reason for not being able to get this running.

I tried calling Vensim DLL today as Bob suggested using the data step below:
data _null_;
CALL MODULE('VdpDLL32,vensim_command',"SPECIAL>LOADMODEL|C:\Research\Intro.vmf");
run;

This time I get an error message from SAS:
ERROR: Write Access Violation In Task [ DATASTEP )
Exception occurred at (02067820)
Task Traceback
Address Frame (DBGHELP API Version 4.0 rev 5)

I am not sure if this genuinely originates from SAS or due to Vensim...

Anyway, I will continue trying to get this Vensim-SAS connection to work either thru DDE or DLL. I would appreciate any pointers along the way...

Thank you...

Burak

Just to check the obvious, but is VdpDLL32.DLL in your c:\windows\system32 directory?

I can't help but notice that the CALL MODULE syntax has mismatched quotes I would expect something more like

CALL MODULE("VdpDLL32","vensim_command","SPECIAL>LOADMODEL|C:\Research\Intro.vmf");

or perhaps using single quotes throughout (or maybe they are interchangeable?)