SafEye
™
™
Series 200 IR Gas Detector - User’s and Maintenance Manual
SPETCREX INC.
Doc. No. TM792100, Rev. B, Oct..1997
- 10 -
Table 1-4. Standard (default) 4-20 mA 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
No gas detection
4-20mA
Continuous measuring of gas concentration at
a range between 0 and 5 LEL
x
m
21mA
Concentration is over the range limit (more
than full scale concentration).
Table 1-5. Discrete reading of 4-20mA at different detector’s modes
Current Reading
Mode
%LEL
x
m
Setting
0+0.5mA
Fault 2 or Low Voltage
-
2±0.5mA
Fault 1
-
4±0.5mA
Standby
0
14±0.5mA
Warning
100
19±0.5mA
Alarm
250
1. 8. 2.
Relays
The detector includes three following relays:
−
Fault relay
−
Alarm relay
−
Accessory relay
The normal position of the alarm and warning relays is open. When in the alarm or
warning status the appropriate relay is closed. The normal position for the fault relay
is closed, and when it is in the fault situation the relay is open.
1. 8. 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 an 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.