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© 2011 Gastech Australia Pty Ltd
2.
Component Parts
2.1
Main Controller Module
The main controller module contains the system program that accepts input signals from connected gas
detectors, processes the measurements and outputs the appropriate signal to the fan. The main module can
be used on its own to form a basic system with 4 input channels.
The Main module comprises:-
4 x 4 - 20mA inputs to connect to gas detectors.
1 x voltage output 0 - 10V to connect to fan driver systems.
5 x volt-free relay contacts to connect to fan driver, beacons, sounders etc.
1 x Digital communication port to connect to the optional graphical display module.
1 x Power input connector.
There are a number of additional features on the main controller but these are used for factory programming
and test and do not need to be included in user applications.
The 'Run' / 'Stop' switch must be in the 'Run' position for the controller code to function.
Signals X0 to X7 are not used in the GTA-VSD20i system. Connection to these terminals is not required.
4-20mA Inputs channels 1 - 3
4-20mA Input channel 4
0 - 10VDC Output control
voltage
Volt-Free Relay Contacts
Main Controller Module (Factory pre-configured)
Optional Extender Module shown fitted
Power-On indicator light
Program running status light
Communication activity to display
Volt-Free contacts status lights
Up to 4 Extender Modules can be added giving
a total of 20 input channels. Each additional
extender requires its own power connection to
be made per the connection diagrams shown
on the following pages.
