1�1�2 20 Ma/Hart ® Output; 1�1�3 Communications � ������������������������������������������������������11 2�2�6 Terminal Block Connections; 1�1�4 Certifications - Honeywell XNX Technical Manual

XNX Universal Transmitter
1.1.2 20 mA/HART Output
®
All XNX Transmitters provide a 20mA Current Loop with HART
Digital Communication which can be user configured for Sink,
Source (3-Wire) or Isolated (4-Wire) electrical interface based on
installation requirements�
The 20mA current loop output provides an analog indication
of special states, a proportional output to gas concentration
and over range indication per the table below� In the event of
a simultaneous alarm and fault, an alarm condition will always
override a warning state�
Output
1�0 mA
2�0 mA
3�0 mA
4-20 mA Gas Concentration
21 mA
*Alarm conditions always take priority over faults and warnings�
HART Protocol provides digital communications with the XNX
from a remote control system for Configuration, Status and
Diagnostics� (See Appendix A HART Protocol for additional
information)
1.1.3 Communications
The XNX Universal Transmitter is registered
with the HART Communication Foundation�
Section 1 - Introduction
Description* Notes
Fault
Special
Warm-up
State
Inhibit
Indication
Bump Test
Calibration
Warning
Over Range
The transmitter uses HART over 4-20mA as the standard
communications protocol� Additional optional communication
interfaces are available: relay communication, Modbus, or
Foundation Fieldbus� Each communication option has a
dedicated option board� For additional information, refer to
Section 1�3 Options�
1.1.4 Certifications
XNX-UT**-****** Versions are UL classified and CSA listed for
installation in Class I, Division 1, Groups B, C and D Hazardous
Locations� FM Approvals evaluation includes Class I, Zone
1, Groups B, C, D, as well as performance tests for specific
sensor/transmitter combinations� CSA/FM certification does
not cover daisy-chained XNX combustible gas transmitters, the
use of HART, Modbus, or Foundation Fieldbus protocols for
combustible gas performance� HART, Modbus, or Foundation
Fieldbus protocols can be used only for data collection or record
keeping with regards to combustible gas� The EC cartridge
EC remote mount kit are UL classified to Canandian and US
standards�
XNX-AM **-***** versions are certified to comply with the
European Community ATEX Directive and the prescribed
protection methods for installation in Potentially Explosive
Atmospheres�
XNX-BT**-***** versions are UL classified and INMETRO
approved (TÜV Rhineland) for compliance with both U�S� and
Brazilian standards�
See Section 6�2 for additional information on applicable
approvals by part number and Section 6�2�1 for marking�
"Cartridge" and "sensor" are used interchangeably in this document�
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