I tried adding opacity from zero to 100, but could see how to repeat the process. I then tried blink, but that didn't seem to make a difference either.

Here is the code I currently have which uses the pre-built blink option:

<script type="text/javascript" src="../ScriptLibrary/jquery-latest.pack.js"></script>
<script type="text/javascript" src="../ScriptLibrary/jquery.easing.1.3.js"></script>
<script type="text/javascript" src="../ScriptLibrary/jquery.dmxzone_animations_pack.js"></script>
<script type="text/javascript">
function dmxAnimate() {//v1.0 
  jQuery.dmxAnimate.apply(this, arguments);
}
</script>
<header id="headerTop">
    
    <div id="logoContainer">
    	<a href="../index.shtml"><img src="../images/logo.png" width="358" height="98" alt="Furbay Electric Supply Co. Home"></a><img src="../images/80th-banner.png" alt="" width="240" height="78" onload="dmxAnimate(this, {'opacity': 1}, {'opacity': 'step:$(fx.elem).css(\'opacity\',Math.cos((fx.now*360*4)*Math.PI/180));'})"/>

I ended up using the built in DW jQuery effect for pulse.

Hello Simon,
Animating opacity from 0 to 1, set the duration, click Advanced and there you ca select "Repeat Forever"