enf656-ocu-ni or enf656-pci-mo? You posted 2 different number.
This is most likely not a Motorola built modem, it only has a Motorola chipset. That chipset is commonly referred to as
SM56 meaning it's a SoftModem, meaning it's a cheap modem built without a hardware processor. Use the first modem driver listed on this page:
http://www.motorola.com/softmodem/driver.htm