What to check

If neither the red LED is on or the green LED reacts to a fob being presented it is possible that the fob reader has failed.

Corrective Action

Check the L1-L6 terminals at both the reader and control unit. 

To prove it's not a wiring fault, wire the reader on a short piece of cable directly to the PinNet controller.

To check that the port on the PinNet controller is not at fault, wire the reader into a different port.

PinNet reader data voltages at idle.  Voltages are approximate and give different readings on AC & DC, see list.

L1    +12v DC
L2    -12v DC
L3    TX data L2 --- L3 0.5v AC
L4    TX data L2 --- L4 8.7v AC
L5    RX data L2 --- L5 2.0v AC
L6    RX data L2 --- L6 5.8v AC

Links