There seems to be very little information available about HUB dimmers, however we have confirmed that dimmer model# M36 use 0 - (-24)V control (zero to minus twenty-four volts).
Two possible resources for info on Hub Dimmers are:
ALM - 847-860-1490
Vara-Light /Dimatronics/ Hub (815) 455-4400
Some installers have had success using our eDIN #1004 module as a replacement control interface for these dimmers. The #1004 card should be set for maximum output (approx 16VDC) and the pots on the Hub dimmers should be trimmed to maximize that output. Please note that while wiring the demultiplexer, polarity will need to be reversed at the dimmer cards. Although the #1004 should automatically source voltage to the Hub controller, please check the documentation that came with your #1004 for correct positioning of the diode shunts on the interface.