Spectrex Xenon 700 SIL Open-Path Gas Detection System - Manual (Page 37)

TM 799200 Rev (C), January 2014
Electrical Specifications 25
 It enables continuous communication between a single standard Modbus
controller (Master device) and a serial Network of up to 247 Detectors.
 It enables connection between different types of Spectrex Detectors or
other Modbus devices to the same Network.
4.2.4.3 Relays Output
The Detector may include up to three of the following relays depending on
the wiring configuration selected.
Table 13: Dry Contact Relays
Relay Type Normal Maximum Ratings
Alarm SPST NO 5A at 30VDC
Accessory SPST NO 5A at 30VDC
Fault SPST NO 5A at 30VDC
Alarm and accessory relays are normally de-energized open. When in the
alarm or warning status the appropriate relay is closed.
Fault Relay is normally energized closed, the contact will be closed, and
when it is in Fault situation, the relay is opened.
4.2.4.4 HART Protocol
The HART Protocol is a digital communication signal at low level on top of
the 0-20mA.
This is a bi-directional field communications protocol used to communicate
between intelligent field instruments and the Host System.
Through the HART Protocol the detector can:
 Display set-up
 Reconfigure set-up
 Display detector status and definition
 Perform detector diagnostic
 Troubleshooting