Nedap uPASS Access User Manual

uPASS Access | installation guide
12/
33
RS485 multi-drop communication
Multi-drop communication requires an addressable communication protocol, such as OSDP.
Termination resistors (120 Ω) are recommended to prevent unwanted signal reflections on long RS485 communication
lines. The resistors should be installed at both ends of the communication line. See Figure 6 below.
Figure 6: RS485 multi-drop communication
Notes
• The uPASS Access reader models before 2020 (Rev. A/B) have a fixed termination resistor, which cannot not be
disabled. This means that these readers should only be used in point-to-point communication.
• Use shielded twisted pair cable when extending the RS485 wiring beyond the standard 5 meter cable.
• Maximum RS485 cable length 1200 meters (
6000 feet).
• The RS485 interface is disabled while the USB interface is in use.
HOST
A
B
120
Ω
120 Ω
uPASS
A
B
A B
uPASS
A B
uPASS

Nedap uPASS Access Specifications

General

Brand	Nedap
Model	uPASS Access
Category	Rfid Systems
Language	English