Connecting Readers

The AI Security Hub supports Accessia Readers and third party OSDP readers

The RS-485 connections to the Readers must use a shielded twisted pair with characteristic impedance in the range of 100 to 120 Ohms

• For example, Belden 8723 cable is suitable, provided that the two RS-485 connections share a single twisted pair

• The RS485 twisted pair must be terminated at both ends with a 120 Ohm +/- 1% resistor

• The Hub has this resistor built in and it is optionally connected using the slide switch. If the Hub is at one end of the Reader wiring (this is the usual case, see Figure 1 and Figure 2) slide the switch to turn the line termination on. If the Hub is in the middle of the Reader wiring (this is possible if two readers are connected to the same channel, coming soon, see Figure 3) then slide the switch to turn the line termination off

• Connect the shield of the cable to earth using the labelled earth post inside the enclosure

Figure 1: Channel with single Reader

Figure 2: Channel with two Readers, shared cable (coming soon)

Figure 3: Channel with two Readers, separate cables (coming soon)