Spectrex Xenon 700 SIL Open-Path Gas Detection System - Manual (Page 36)

SafEye TM Xenon 700S SIL Gas Detector
24 Electrical Specifications
4.2 Electrical Specifications
Operating Voltage: 18-32 VDC
4.2.1 Power Consumption
Table 12: Detector and Source Maximum Power Consumption
Without Heated
Optic (Max.) With Heated
Optic (Max.)
Detector 220mA 300mA
Source 220mA 300mA
4.2.2 Electrical Input Protection
The input circuit is protected against voltage-reversed polarity, voltage
transients, surges and spikes according to MIL-STD-1275B.
4.2.3 Electrical Interface
There are three output-wiring options. These options must be defined at
factory per the customer order. See Appendix B for wiring/terminal diagram
for each option.
Note: Option 3 is the default unless otherwise specified at time of order.
 Option 1:Power, Alarm Fault Relay, 0-20mA (Figure 9).
 Option 2:Power, Alarm, Fault & Accessory Relay(Figure 10)
 Option 3: Power, Alarm Relay, RS 485, 0-20mA, RS-485 RTN (Figure 11)
Note: SIL2 covers only 0-20mA outputs.
4.2.4 Electrical outputs
4.2.4.1 0-20mA Current Output
The 0-20mA is isolated sink option. This output can be configured as Source
– see Appendix B.
The maximum permitted load resistance is 600 ohm.
Two 0-20mA options:
 Continuous reading – default (see Table 2)
 Discrete reading (see Table 3)
4.2.4.2 Communication Network
The Detector is equipped with an RS-485 communication link that can be
used in installations with computerized controllers.
Communication is compatible with the Modbus protocol:
 This protocol is a standard and is widely used.