The GCSpro 2000 is a two door controller extending to a total of sixteen doors via GCSpro door stations. In turn up to 128 GCSpro 2000s may be networked via a PC interface to facilitate up to 2000 doors. The GCSpro 2000 can be configured and maintained standalone or through GCSWin pro PC software. The GCSpro 2000 may be networked via RS485 interface.