Specifications

Alto 818 Installation and Operation
2-32 P/N 66109074001 Rev. D
2.12 S-NET
S-Net is a serial network for communication between the ACU and digital node devices such as
DigiReaders and the VIP2 keypad. Typically, the cable used is two twisted pairs with an overall
shield; one pair is for data, the other pair is for DC power. Terminate the S-Net with 120-ohm,
¼ watt resistors as shown in Figure 2-14. The maximum S-Net length is 4000 feet (1200 meters).
Figure 2-14: S-Net Wiring
S-Net cable should be installed as a single cable without splices or T's. If an installation requires
a drop-line to a DigiReader or other device, the line should not exceed 6 feet (1.85 meters) in
length.