Honeywell XCD Manual
The Sensepoint XCD (“Exceed”) comprises a gas detector transmitter and a choice of sensors for detecting flammable gas, toxic gas and oxygen. The construction of Sensepoint XCD allows it to be used in hazardous area locations; it may also be used in other areas not classified as hazardous.
As well as a comprehensive range of Sensepoint XCD sensors, a wide range of existing Honeywell Analytics sensors may be used with the Sensepoint XCD transmitter to detect a broader range of target gases (please contact Honeywell Analytics for further details).
The transmitter features a display and three programmable relays for controlling external equipment e.g. alarms, sirens, valves or switches. The transmitter provides an industry standard 3-wire, 4-20mA source or sink output for connection to a dedicated gas detection control system or PLC.
Calibration and maintenance is carried out using a Magnetic Wand, this allows a single user to undertake routine maintenance without needing to access internal components. Sensepoint XCD is suitable for use in Zone 1 or 2 hazardous areas (International) or Class I Division 1 or 2 area applications (North America).
Options
Modbus® (Modbus option not tested as part of the performance approvals) One of the most common field buses in the industry, the optional Modbus® interface allows the XCD to connect to a bus of devices and transmit data to PLCs or controllers (see Appendix A). Connections to the XCD are made through a pluggable terminal block on the Modbus® interface circuit board. Modbus® RTU protocol uses ASCII/Hex protocols for communication. and allows all transmitter/sensor front panel functions to be transmitted using this industrial fieldbus. Modbus® protocol is a Master-Slaves protocol. Only one master (at the same time) is connected to the bus and one or up to 32 slave nodes are also connected to the same serial bus. Modbus® communication is always initiated by the master. The slave nodes will never transmit data without receiving a request from the master node. The slave nodes will never communicate with each other. The master node initiates only one Modbus® transaction at the same time. Modbus® option is available only for selected gases. Please refer to chapter 15 Ordering information. To find out if a unit has the Modbus® option fitted, look at the part number on the product label. Units fitted with Modbus® have the letter “M” at the end of the part number.
System Status
Display indications, current output and relay states for various operational conditions
are shown in the following table. For further details of error messages and trouble shooting
see section 12.3.
Normal Operation
Sensepoint XCD is supplied configured and ready for use according to the “Default Settings” table shown above. However these setting may be tailored to a specific application requirement using the Sensepoint XCD configuration menu system.
Access to the Sensepoint XCD transmitter’s configuration menus system is via the Magnetic Activation Tool.
Display Screen
The Sensepoint XCD display features an LCD with Numeric and bar-graph gas concentration data, alpha-numeric warning and status indication, a target for magnetic switch activation and the UP/DOWN/ESC/ENTER zones for remote configuration. The LCD is also backlit with hi-intensity multi-colour LED indicator to show NORMAL, ALARM and FAULT status.
During normal operation the instrument display shows a steady GREEN backlight.
During Low and High Gas Alarm it displays a flashing RED backlight
During Fault condition the instrument display shows a flashing YELLOW backlight. The screen is visible through the window of the transmitter’s cover. The display shows the gas concentration (both graphically and numerically), range, units, alarm/ fault status, etc.
Note: The detector display may become sluggish in sub-zero temperatures and possibly unclear at temperatures below -40 °C, but the detector continues its gas monitoring function. The display is not damaged and recovers when the temperature increases.
