Ampcontrol gasguard, Инструкция по установке, эксплуатации и обслуживанию

Страница: 11 / 79

GASGUARD IS CONTROLLER Issue: R2, Date: 26/09/2011, CRN: 7502
Page 10
2.5 Overview of the Gasguard Controller
2.5.1 Basic Description
The Gasguard Programmable Intrinsically Safe controller (Controller) produced by Ampcontrol is designed to operate
with a variety of hazardous area certified gas detectors. Compatible detectors are presently supplied by Ampcontrol
and other manufacturers.
The Controller is supplied with either two or four programmable input channels (see Parts List in Section 8 of this
Manual for details).
Input channels may be supplied to operate with a 4-20mA current input signal or a 0.4 - 2.0V voltage input signal.
This configuration is fixed by the manufacturer and is not user modifiable.
Each input channel is independent of the others and can be configured on a ‘per-channel’ basis allowing flexible
system configuration.
2.5.2 Input channels are user configurable, and may be:-
• Set to be ON or OFF.
• Given a name to represent its function.
• Selected to display one of a number of gas types.
•
Configured to display one of a number of measurement units.
•
Configured to display from none to two decimal places.
•
Scaled to a user defined maximum value, ranging from zero 9999.
Each input channel has three programmable ‘set-points’ which can be set to trip based on the signal input level.
2.5.3 Each set point may be:-
• Set to operate at a specific channel input level.
•
Set to operate with hysteresis.
•
Set to operate in a particular direction (rising signal or falling signal).
•
Operate immediately or after a user configured delay.
•
Set to latch an alarm indication or auto-reset.
In addition to the input based set-points, there are two ‘fault’ set-points. These set-points are referred to as High-
Fault and Low-Fault.
2.5.4 High and Low Fault set-points may be:-
•
Set to operate at a specific channel input level.
•
Set to operate on a rising or falling input signal.
The controller has four relay outputs, mappable to alarm set-point from any channel.
2.5.5 Each of the four relays can be set to:-
• Latch. This feature may be used to preserve a record of a relay’s state in the event of a power failure or to
record an alarm event where there may be no one to respond to it at the time it occurs.
• Be normally energised or normally de-energised.