Termination and addressing
The three examples on the left in the figure show permitted examples of connecting communication between readers and door control units. Depending on the connection, the communication loop is terminated either in:
- In door controller and one reader.
- In both readers
The framed example on the right shows an unauthorized connection, where the communication loop to two readers has been branched between the door control unit and the reader.
| A77/A73/A71/ | A45/A45i | B28/ B27/B17 | B18 | |
| Termination | Install the 120 Ω resistor between 5 and 6. | Install the termination jumper. | Install the termination jumper block | mount a 120 Ω resistor (supplied) between terminals 3 and 4. |
| Addressing reader B * | Install wire jumper between terminals 7 and 8. | Remove the addressing jumper. |
* Readers are named in the VAKA software.