[Zope] timeout on external methods?

[Granzow, Doug (NCI)]

I have a page in Zope which calls a Perl script via an External Method.  The
perl script takes a long time to complete -- about 8 minutes.  After exactly
5 minutes, I see a second perl process launched by Zope.  At 8 minutes, the
first perl process completes, but I do not see the response in my browser.
After 10 minutes, I get "This page cannot be displayed" in my browser, but
the second perl process is still running.

Does Zope have a timeout that is causing it to re-try the perl script after
5 minutes?  Is this adjustable?