Security specialists Tensor provides a door entry Smart Card Access Control system that can include barriers, gates and visitor monitoring. The T3511 Door Access Controller can be linked to up to 128 other T3511s. The T3511 is the ideal way to start off small, but to have the flexibility to grow at a later date. This is so much better than installing a door controller that only operates as a 'stand alone' unit with no future expansion capability. The modem facility within the T3511 enables you to install a simple system at a remote graphical location where there is only power and a phone line.