Xylem PC320 Process Controller - Manual (Page 11)

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VIII. Power Saving Mode
A power saving mode is provided that allows the operating current to be reduced in
remote monitoring applications. One way this is accomplished is to turn off the LCD
display backlight, this saves about 20mA of current. Three modes allow the user to
turn the backlight on all the time, off all the time, or turn it on for one minute only. In
this last mode, the backlight will come on for one minute when any of the buttons on
the keypad are pressed, then turn off again after one minute of inactivity. The sensor
can also be turned on and off periodically to reduce power consumption. The user can
program a sample rate of 0-60 minutes, and can set the sensor warm-up time of 0-60
seconds. Example: The sample rate is 30 minutes and the warm-up time is 3 seconds.
The sensor will be turned on for 3 seconds every 30 minutes then shut off again.
During the time the sensor is off the LCD display and 4-20mA output will indicate the
last sensor reading. The relays will continue to operate, based on that last reading.
After 30 minutes more, a new reading will be taken and the display and 4-20mA
output updated again. Note that using the 4-20mA output will increase the current
draw by an amount equal to the output current. It is also possible to fail to react to
rapidly changing events.
IX. Scientific Notation
Scientific notation is used in the PC320 for entering parameters for the Polynomial
mode and is generally used for displaying very large or very small numbers. It
represents a number as being multiplied by 10 raised to a power, such as 5.67*10^2
being equal to 567 since 10^2 equals 100 (10^2 = 10²). The notation E2 is also
equivalent to “shift the decimal point to the right two times”. This makes the display
of large and small numbers easier to read; 5.67E3 is 5.67 thousand or 5670, 5.67E6 is
5.67 million, etc. In the same way, small numbers less that one can be shown as 10
raised to a negative power, or “shift the decimal point that many times to the left”;
such as 5.67E-3 = 0.00567 or 5.67 thousandths, 5.67E-6 = .00000567 or 5.67
millionths.
X. Programming Setup Parameters
Press the MENU button for 2 seconds to enter the setup menu. Pressing the MENU
button again cycles through the different setup options. Pressing the BACK button
moves backward to the previous display. Pressing the DISPLAY button from any
menu exits setup and returns to the normal display mode. Press the RIGHT arrow