So worked with ALC and Sitescan and the other OEM versions for a while. The modbus driver for the sitelink is the same as webctrls. Look in the webroot folder of sitescan and find the System folder. Go to drivers in it and the driver for modbus should be there. Also i would copy the drivers from the sitescan system. Alot of them will load directly into ALC controllers which comes in handy sometimes.