MSA GasGard XL Instrucciones Para El Usuario página 8

2 Description
2.1.6 Sensor Extension Board
The sensor extension board is used to:
• attach channel boards
• connect internal communication.
NOTE: See 3.4 S ensor Connection.
2.1.7 Channel Board
The channel boards are set to communicate with 4-20 mA transmitters.
Every board:
• includes four LEDs (A1, A2, Status, Power)
• attaches to the Channel connectors (four on the Main board, four on the Sensor Extension board).
Sensor power and connection is designed as "fail-safe"
(wrong connection/configuration does not damage the remote sensor).
2.1.8 Channel Relay Board
Every Channel Relay board:
• provides eight output relays
• is connected to the Main board or Sensor Extension board (one by one) via connectors.
Relays are fully user-configurable from the front panel or connected PC via configuration software.
Two optional SPDT (Single Pole Double Throw) relays per channel (eight relays per four channels) are configurable for
individual alarms:
• Normally open/closed
• Normally energized/de-energized
• Latching/non latching
• Increasing/decreasing
• N out of m voting
• Grouping
NOTE: Contacts are resistive load.
2.1.9 Front Panel
The Front Panel enables communication with the Control Unit and is used to:
• monitor the status of all connected field sensors
• determine system settings
• configure all s ettings.
9 GasGard XL US