User Manual

Model 2200P Page 11
4.5 Analog Outputs
4.5.1 The analog output signals consist of a non-isolated 0-1 mA, 0-5 Vdc, and isolated 4-
20 mA signals.
4.5.2 From the factory all of the analog outputs have a linear range corresponding to the
full range of the instrument. The outputs can be scaled to another linear range by
entering two values:
• Output High: This is the pH value at which you wish to have 100% output.
• Output Low: This is the pH value at which you wish to have 0% output.
4.5.3 When programming, you must ensure that the output range has a span of at least
10% of the full range of the instrument. For applications that require the output to
decrease as the process value increases, i.e. an inverted output, the Output High
value will be less than the Output Low. See Section 5.4.
4.5.4 The instrument may be used to monitor the temperature of the process, in either (C
or (F. The 2200P does not control temperature but the 0-5 Vdc and 0-1 mA analog
outputs can be dedicated to follow the process temperature. See Section 5.14.
4.6 Operation Menu
4.6.1 The operation menu allows the user to recall and to adjust the parameters, required
by the analyzer functions.
4.6.2 When the analyzer is powered up, the program will display pH readings and the
STATUS indicator above the display will be green. None of the LEDs in the
operation menu will be illuminated.
4.6.3 Five buttons on the panel are used to operate the menu. Use the MENU button to
step through the items in the menu. The red LEDs beside each menu item makes it
very easy to follow the menu. The function of the RUN button is to return to the on-
line pH display from anywhere in the menu. The analyzer has a built-in timer, which
returns the unit to the online mode if no button has been pressed for 10 minutes.
This time-out has the same effect as pressing the RUN button.