This is the distribution of the plate:

The board has the following ports for reading entries:
UART0, UART1: to connect RS232 card readers
TTL1: to connect card reader.
Connector molex 4 connectors: normally for the fingerprint reader.
Connector molex 5 connectors: TTL reader.
It also has 4 relays that are used to open lathes or doors, are no more than electronically controlled switches:
Rele0, Rele1, Rele2, Rele3.

RJ45 connector: for connection to the network
Display connector: In case they are supplied in box, for the display of 2 lines that have built-in.

Inputs: To connect alarms, loops for the presence control of vehicles in the parking lot.
External buzzer: output ttl levels to activate external sirens.
Led's: output ttl levels for the activation of external led's.

Besides the plate has a buzzer to indicate errors or confirm readings.