3.3.3 Alarm Connections
The Model 6750 is equipped with two concentration alarms and
one analyzer malfunction alarm. The three alarm-circuit connectors use
spring terminals for making connections to internal alarm relay
connects. Each alarm provides a set of Form C contact with both
normally open and normally closed contact connections. The contact
connections are indicated by diagrams on the rear panel. They are
capable of switching up to 3 amperes at 250 VAC into a resistive load.
See “As Built Drawings” in the Appendix. The connections are:
• Threshold Alarms:
• Can be configured as high (actuates when concentration
is above setpoint), or low (actuates when concentration is
below threshold).
• Can be configured as failsafe or non-failsafe.
• Can be configured as latching or non-latching
• Malfunction Alarm
3.3.4 RS-232 Serial Connection
An RS-232 port is provided for serial communication (MODBUS).
Connect a standard RS-232 cable from the computer to the RS-232 port
on the main board.
3.4 Gas/liquid Connections
Refer to the “As Built Drawings” in the Appendix for details and
Figure 3-5.
The Model 6750 Analyzer provides easy access for liquid, gas, vent
and drain connections.
3.4.1 Liquid Connections
Liquid phase sample connections include the following: (See
Figure 3-5):
• Sample (On-Line)
• D. I./Dilution Water
• Calibration Standard
