Instruction manual

79
Interlock Outputs
Click the check boxes to select or de-select the relays that you want to be forced OFF if this output
relay is turned ON. If you do not need any other output to shut off when this relay turns on,
UNCHECK all boxes. The selection is mutually exclusive, meaning that if the Feed output has the
pH output interlocked, the feed won’t turn on if the pH output is on, and the pH output won’t turn
on if the Feed output is already on. This feature should be used with caution since it can
potentially delay a chemical addition for a long time. Typical uses are to prevent inhibitor feed
during a biocide addition, or to prevent bleed and pH control during inhibitor feed.
Output Mode
Click on the radio buttons to manually control the Dispersant relay. The normal selection will be
Auto, where the controller uses the various set points to open and close the relay. You can force
the relay open (pump off) regardless of the set points by selecting Off, or force the relay closed
(pump on) regardless of the set points by selecting Hand.
If you select Off, the pump will not run again until either Hand or Auto is selected! If you select
Hand, the pump will run until either Auto or Off is selected, or until the Hand Time Limit
(programmed in the next menu) expires.
The Off mode is handy to prevent the pump from running while you are changing set points. The
Hand mode is handy to be able to test the pump, wiring, etc without needing to change set points.
Hand Time Limit
Type in the text box the maximum number of minutes that the Dispersant output can be activated
in the Hand mode. Any value between 0 and 1440 is acceptable. A value of 0 means the output can
be left on indefinitely.
Click on the “Submit” button to save the changes.
Event Log
Click on the link to view the event log. The event log contains the date and time of each relay
activation and deactivation. The data will be a 1 if the relay is closed and a 0 if the relay is open.
The log also shows the state of the flow switch, with a 1 denoting flow, and a 0 denoting no flow.
A window will open to ask if you would like to open the file or save it to disc. Select the method
you would like to use. The file is a .csv (comma separated variable) file that will open in a
spreadsheet such as Excel.
6.23 pH Output Menu (only appears if a pH option card is installed)
pH Control Mode
Click on the radio button of the option that matches your installation:
Direct pH Sensor should be selected if you will be controlling the pH relay based upon a signal
from a pH electrode.
Other (4-20 mA input 6) should be selected if you will control the pH relay based on a signal
from a transmitter that is connected to 4-20 mA input 6. This option is only possible if your
controller is equipped with the analog input option card.