It would be well worth your time to download the zip attached to the first post here:
http://modxcms.com/forums/index.php/topic,13533.0.html
I think you are looking for the "Summary" Extender section
c-m
I use this on every site I build. Here is my actual Ditto chunk:
<div class="ditto_summaryPost">
<h5><a href="[~[+id+]~]" title="[+title+]">[+title+]</a></h5>
<div class="ditto_info" >[+createdon:date=`%B`+] [+createdon:date=`%d`+], [+createdon:date=`%Y`+] | <a href="[~[+id+]~]#commentsAnchor">Comments
([!Jot?&docid=`[+id+]`&action=`count-comments`!])</a></div>
<p> [+summary:limit=`190`+] ... <a href="[~[+id+]~]">Go »</a></p>
</div>
<br clear="left" />
The ’summary:limit=’ is where the characters get limited. One thing to note, it is all characters that are counted, even img code. You can go to my site to see it in action. I use this to keep the columns equal height:
http://impress-design.com
There are no boring projects. Only boring executions. ~ Etzkorn
www.impress-design.com
In your chunk where you have: [+summary+] change it to: [+summary:limit=`50`+]
There are no boring projects. Only boring executions. ~ Etzkorn
www.impress-design.com