<?php // Product Short Description
if(!empty($product->product_s_desc)) { ?>
<p class="product_s_desc">
<?php echo shopFunctionsF::limitStringByWord($product->product_s_desc, 80, '...') ?>
</p>
<?php } ?>

<?php // Product Short Description
if(!empty($product->product_s_desc)) { ?>
<p class="product_s_desc">
<?php echo shopFunctionsF::limitStringByWord($product->product_s_desc, your_limit_number, '...') ?>
</p>
<?php } ?>

<?php // Product Short Description
if(!empty($product->product_s_desc)) { ?>
<p class="product_s_desc">
<?php echo $product->product_s_desc; ?>
</p>
<?php } ?>