Russ,

44 times a second is not a bad refresh rate. The DMX spec allows upto a 1Hz refresh rate, although the fades look a bit 'jumpy'. I own a Martin Lightjockey system and it has the options for 44Hz, 22Hz and 11Hz transmission.

44Hz is fine for most moving rigs. Personally I have code that will transmit DMX from a PIC at 80Hz, but that runs a tight loop with only 24 channel frame, but have found that a quick refresh can sometimes freak out some of the cheaper Chinese style scanners.

The Enttec stuff is great, but I would recommend the USBPro interface as it is also isolated and has some more funky software options.

From the Enttec site on the USB Pro: http://enttec.com/index.php?main_men...name=dmxusbpro
<snip>
# Refresh Rate configurable from 1 to 40Hz with a full 512 channel frame
# Break configurable from 96uS to 1.3mS
# MaB configurable from 10.6uS to 1.3mS
</snip>

Bill.