Manual

Spectrex Inc. - SafEye

200 Gas Detector Manual – TM 792100, Rev. D, May 2004

Table 4. Standard (default) 4-20mA Current for the Gas Channel

Current Status and Description

0mA +0.5mA Fault 2 or Low Voltage

2mA ±0.5mA Fault 1

4mA ±0.5mA Zero reading - No gas detected

4-20mA Continuous measuring of gas concentration at a range

between 0 and 5 LEL.m or full scale

21mA Concentration is over the range limit (more than full scale

concentration).

Table 5. Discrete reading of 4-20mA at different detector’s modes

Current Reading Mode LEL.m Setting

0 +0.5mA Fault 2 or Low Voltage -

2 ±0.5mA Fault 1 -

4 ±0.5mA Standby 0

14 ±0.5mA Warning 1

19 ±0.5mA Alarm 2.5

3.7.2 Relays

The detector includes three relays:

• Fault relay

• Alarm relay

• Accessory relay

Fault Relay contacts are normally energized closed, and opened when in Fault

condition

3.7.3 RS-485 Interface

The RS-485 input/output sends complete data information to a PC and receives

data or control commands from the PC. The communication with the PC is

operated through this interface is executed only when used with appropriate host

software.

The following PC minimal hardware requirements are as follows:

• 386 PC using DOS Ver. 5.0 or higher

• 1 MB RAM.

• 2 MB free hard disk space.

• 1.2 or 1.44 MB floppy drive

• Color VGA

• RS-485 Interface Card to be defined as COM1 or COM2. Isolated Adapter

is preferred.