Rs-485 Conversion Board; Rs-485 Conversion Board Connectors - Honeywell CNI2 Operating And Installation Manual

CNI2 Operating and Installation Guide

RS-485 CONVERSION BOARD

The RS-485 conversion board is shown below. External wiring connections are accomplished
using terminal block TB1. The number of connections will depend upon whether the link is half
duplex or full duplex. Although the full duplex wiring method requires two additional wire
conductors, it is typically simpler to deploy and service in the field.
JP1 - When installed this jumper places a 120 ohm termination load on the RX end. For most
installations this jumper should be installed.
JP2 - When installed, this jumper places a 120 ohm termination load on the TX end. For most
installations this jumper will not be installed.
JP3 - When installed this jumper reduces the bandwidth of rise and fall transition edges of the
transmit signal to minimize signal reflections (similar to echo's) on the cable. For most
installations this jumper is not installed.
JP4 - Selects half duplex or full duplex mode. Position A+B is half duplex, and B+C is full
duplex.
NOTE
If you are using half duplex operation you must select the "RS-485 Half Duplex" setting on
the Serial Port Settings configuration screen.
Honeywell has a document available that further details the RS-485 theory of operation and how
it applies to this particular board. A Product Support Specialist can provide a copy of this
document in PDF format upon request.

RS-485 Conversion Board Connectors

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