Metex 2200P pH Analyzer/Controller - Manual (Page 19)

Model 2200P Page 17
5.4 Analog Output Range Expand
5.4.1 To increase the resolution of the analog outputs, the range may spread over any
section of the scale. as long as is spans at least 10% of full scale. The best way to
describe this setup is by example. Suppose you wish the outputs to span from 4 pH
to 10 pH. Proceed as follows:
a) Enter the menu by pressing MENU until the OUTPUT HIGH LED is illuminated.
Use the arrows keys to make the display read 10.00. Press ENTER. The
display will flash until ENTER is pressed again to confirm the value.
b) Press MENU and the OUTPUT LOW LED will illuminate. Use the arrow keys to
make the display read 4.00. Press ENTER. The display will flash until ENTER
is pressed again to confirm the value.
c) The analog outputs will now be at 0% when the pH is 4, and will increase to
100% when the pH of the solution is 10.
d) Press RUN to place the instrument on line, or press MENU for another menu
selection.
NOTE: A range expand of less than 10% of full scale is an invalid entry which will
be indicated by the LED flashing when you return to RUN. To correct,
return to the menu and correct the output settings. If an inverted output is
required program output low higher than output high. This will cause the 4-
20mA output to decrease as the process increases.
5.5 Control Relay A Relay On
5.5.1 The Control Relays are configured by programming the Relay On and Relay Off
Setpoins.
As shipped from the factory, Control Relay A, is configured to control decreasing
pH. However, you may change the direction of the relay by changing the position of
the DIP switch. (Refer to Section 4.7)
5.5.2 The relay on setpoint may be set at any point on the scale.
To program the setpoint. Proceed as follows:
a) Enter the menu by pressing MENU, proceed by pressing MENU until the
RELAY A Re\ELAY ON LED is illuminated. Now use the arrow keys to make
the display read the desired value. Press ENTER. The display will flash until
ENTER is pressed again to confirm the value.
b) Press RUN, to place the instrument on line, or press MENU for another menu
selection.