TS1061 Dual Wiegand Interface Installation Manual
11
Terminating the RS-485 LAN
All Challenger
LAN devices (including the panel) use a 470 Ω LAN termination
resistor where required. LAN termination resistors are used to set the impedance
of the LAN to around 220 Ω in order to minimise noise. The termination resistor
may be external or on-board (devices with an on-board resistor use a link to set
the LAN termination to ON).
A Challenger LAN should have only two devices with the LAN termination set to
ON (or the LAN termination resistor fitted):
• In a straight LAN configuration, the TERM links are ON at the Challenger
panel and the most distant device.
• In a star LAN configuration, the TERM links are ON at the two devices that
are the furthest apart (and OFF at the Challenger panel).
In a completely connected (but powered down) system, you can check for correct
LAN termination by measuring the resistance across the D+ and D− terminals:
• 0 Ω indicates a short circuit in the cabling
• 160 Ω or less indicates that too many devices are terminated
• 220 Ω is good
• 470 Ω or more indicates that not enough devices are terminated
Lock power
Additional power for locks can be supplied from a Network Access Controller via
the 2-pin plug-in lock power socket (Figure 2 on page 8, item 8). Connect a
2-way lock power cable (supplied) to the 2-pin plug-in lock power socket to
provide additional power for locks.
Refer to Figure 3 on page 10 for example connections of the 2-way lock power
cable from a Network Access Controller to the Interface (items A and C).
Note:
Refer to the
TS1066 Network Access Controller Installation Manual
for
information on the maximum total current draw allowed from a Network Access
Controller.
