Let’s have a look to the Linear AM3 Plus Access control panel.
It is capable of controlling up to 4 doors, expandable up to 32 doors, up to 10.000 users and 20.000 entry codes . It has four built-in general purpose (Form “C”) relays. Anyone can be used for the control relay and the others for auxiliary control functions, including activation of safety edge reverse, or alarm shunting. In addition, the AM3Plus supports request to exit and door status monitoring for each relay. The AM3Plus is supplied in a lockable plastic enclosure designed for indoor use. For outdoor mounting, an optional NEMA 3R enclosure (Model CAB-3) is available. There are two programming choices: Use any PC at any location to access programming using Linear's AXNET that is built into the controller. Or use a dedicated PC to access programming using Linear's AccessBase2000 software. Both choices allow multiple unit connectivity.
Other features include:
Front Panel: two 7-segment LED displays for system configuration, status and troubleshooting PBUS: two sets for connecting up to six proprietary addressable devices Wiegand: two sets of Wiegand inputs for connecting 26, 30, or 31 bit Wiegand devices; each Wiegand input supports two reader LED indicators.
Request To Exit: four normally open inputs; each input assigned to specific relay
It is 12/24 VAC or VDC; 16 VAC transformer is included, the operating temperature is -22° to +149°F, dimensions are: 11.5 in L x 4 in W x 12.5 in H (292 x 102 x 318 mm), it comes with Built-in 24-hour clock/calendar with battery back-up and daylight savings adjustment.