Measurement Computing PointScan 100 Series rev.1.0 - Manual (Page 13)

PointScan/100 User’s Manual 9-12 - -01 Ethernet, RS485 Wiring 2-1
Ethernet, RS485 Wiring 2
Ethernet Wiring Guidelines
PointScan/100 I/O modules communicate with a master device (PC) using 10BaseT Ethernet media.
Electrical isolation is provided on the Ethernet port for increased reliability. Follow normal Ethernet
wiring practices when installing PointScan/100 I/O modules.
RS485 Wiring Guidelines
PointScan/100 I/O modules also feature an RS485 port for I/O expansion via PointScan/200 I/O modules.
The RS485 party-line consists of two wires and an isolated ground wire. It is recommended that the ground
wire be connected to all stations to provide a common return. The RS485 port on all PointScan/100
modules is isolated from its internal circuitry, local power source, and I/O wiring to improve
communications reliability. It is recommended that only 32 PointScan/200 or PointScan/100 modules
(Configured for RS485 communication) be connected on any RS485 party-line, and that the termination
jumper be installed on the last module on each end of the RS485 network. Limiting the cabling to two
network arms (segments) radiating from the master controller will yield the best signal results.