Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 Master Module Installation Instructions - Manual (Page 40)

40 Powermonitor 3000 Master Module
Publication 1404-IN007F-EN-P - November 2009
Optional Remote I/O Communication
Powermonitor 3000 units with a catalog number ending in -RIO are equipped with a remote
I/O port in addition to the native RS-485 port. Allen-Bradley remote I/O is a robust, widely
used industrial data network that uses twinaxial cable as its physical media. The power
monitor emulates a logical quarter rack and supports both polled I/O and block transfer
communication. The remote I/O port and the native RS-485 port may be used
simultaneously, although overall data throughput may be reduced.
Remote I/O communication wiring should be installed in a daisy-chain configuration. We
recommend that you use Belden 9463 twinaxial cable or equivalent. The maximum cable
length is shown in the Remote I/O Communication Rates table and varies with the data rate.
Use of a star or bridging topology is not recommended and will result in signal distortion
unless impendance is matched for each spur (star topology) or network (bridge topology).
Be sure that all devices on your remote I/O network are capable of operation at the desired
communication rate. Certain legacy devices may not support a 230.4 Kbps communication
rate.
Install suitable terminating resistors at the ends of the remote I/O network.
At each end of each cable segment, connect the cable shields to the SHLD terminal of the
remote I/O port connector. The SHLD connection provides a low-impedance ground for
high-frequency noise while attenuating DC or line-frequency signals. We recommend that you
follow the standard blue/shield/clear color scheme for remote I/O to differentiate it from
Data Highway Plus (clear/shield/blue) cables.
Remote I/O Communication Rates
Communication Rate Distance, Max Terminating Resistor
57.6 Kbps 3048 m (10,000 ft) 150 Ω, 1/4 W
115.2 Kbps 1542 m (5000 ft) 150 Ω, 1/4 W
230.4 Kbps 762 m (2500 ft) 84 Ω, 1/4 W
TIP
Some remote I/O devices are equipped with internal terminating resistors.