Beginning with Power Search version 5.1090 you can automatically (with cron) run a mirror rebuild from a 
standard Miva Merchant page template in merchant.mvc.  This method also requires that you have the 
Emporium Plus Tool Kit version 5.163 or newer.  

1) Since the page is not password protected, you would not want its name to be known to the general public.  
You might have a person or automated program continually running the page in an effort to drain your 
server's resources.  With this in mind, create a new page template with a code which is not easy to guess.  
Below is the example store morph code for the new page template.  When this page is run in merchant.mvc you
will also pass a name value pair that is an additional check before the code on the page runs.  An 
example url might be http://www.YOURDOMAIN.com/YOURPAGE.html?runps=123  You would replace the domain and
page applicable to your store.  The name value pair would also be unique to your store.

<mvt:if expr="g.runps EQ '123'">
<mvt:item name="toolkit" param="sassign|powrsrch_rebuild|400" />
<mvt:item name="toolkit" param="sassign|powrsrch_fulltext|name,descrip" />
<mvt:item name="toolkit" param="sassign|send2email|xxx@xxxxxx.xxx" />
<mvt:item name="powrsrch" param="rebuild" />
<mvt:if expr="g.pscron_continue">
	<mvt:item name="toolkit" param="sassign|newurl|http://www.YOURDOMAIN.com/YOURPAGE.html?runps=123%querystring%" />
	<mvt:item name="toolkit" param="vglosub|g.newurl,%querystring%,g.PSQueryString" />
	<mvt:item name="toolkit" param="headeroutput|Status|301 Moved Permanently" /> 
	<mvt:item name="toolkit" param="vheaderoutput|Location|g.newurl" /> 
</mvt:if>
</mvt:if>

Line 1 of the above template tests for your name value pair to be correct.  A mischievous person would have
to know the page name just to get to the page.  Then they would have to know the variable name and its 
value before the code on the page would even run.  

Line 2 sets the number of records to read before the screen is refreshed.  If you experience time outs, 
reduce that number.

Line 3 sets the fulltext index fields if you are using MySQL in your store and you want to have the 
fulltext search feature.  See the usage doc about this setting.

Line 4 is the email address you want to notify when the mirror is built.  If you do not want email
notification, you still need to have line 4 to assign a nul value to the send2email variable.  You 
would do that by removing the third parameter of that line.

Line 5 runs the mirror rebuild.

Lines 6-11 are conditional code that run when the rebuild needs to refresh the page to avoid timeout.  Only
line 8 needs editing.  Lines 9-11 execute a 301 redirect so that the cron will keep running.

Line 7 is the url that runs when multiple passes are needed to complete the rebuild.  Change the YOURDOMAIN
and YOURPAGE as applicable.  Also change the name value pair to match what you used in line 1.

You can test your settings by running it from your browser.  As it runs, it will appear nothing is happening. 
After the report has run completely, it will display the number of products in the mirror and the approximate
processing time.

2) If you have run the rebuild successfully from your browser, you can go to the next step.  You will create 
a cron task in your site's panel.  Your host needs to give you the access info for that panel.  Set the run 
time for whatever you want.  Then in the command line, you will have something like this:

wget --post-data='Screen=YOURPAGE&Store_Code=YOURSTORECODE&runps=123' http://www.YOURDOMAIN.com/mm5/merchant.mvc >/dev/null 2>&1

Change the domain, store code, page name and name value pair as applicable to your setup.  At the end of 
the command line above you see a string of characters.  Those suppress actions which you do not want/need. 
I suggest you keep them as shown.