Rs-232 Multiplexer Board; Serial Rs-232 Multiplexer Board - Honeywell CNI2 Operating And Installation Manual

CNI2 Operating and Installation Guide

RS-232 MULTIPLEXER BOARD

The RS-232 multiplexer is shown below. The connector J3 is pre-wired at the factory to the
CNI2 board. When the RS-485 board is not included with the assembly then both serial ports
are available for connection to external devices. An example might be two ECAT electronic
correctors at a field site.
If the configuration has both the multiplexer board and the RS-485 as part of the system, then
only terminal block TB2 is available for wiring to an external RS-232 device. TB1 will have been
pre-wired to the RS-485 board, which has its' own connector for external wiring to an RS-485
compatible instrument.
Please note that the TXD line is a driven output, RXD is an input, DSR is a driven output, and
DTR is used as a wakeup trigger. The following page describes the DTR function and wiring
connection in more detail.

Serial RS-232 Multiplexer Board

43