3.6
Analog Outputs
Voltage
measuring
Current
measuring
D connector
J612
on the rear panel provides the monitor outputs. The
following pins can be used for voltage and current metering:
• Pin 8 measures voltage (and pin 1 measures ground)
• Pin 7 measures current (and pin 1 measures ground)
Ion pump voltage can be obtained by measuring voltage at pins 8, 1
and applying this formula:
V
1p
= V
M
ON
X
3333
For example, if 2.4V is measured, ion pump voltage is 8000V.
To obtain ion pump current, measure voltage at pins 7, 1
and apply this formula when
monitor jumper W301
(located on CPU
board) is installed:
l
1p
(m A)= V
M
oN x 0.333
If0.09V is measured, ion pump current is 30 mA.
or apply this formula when
monitor jumper W302
(located on CPU
board) is installed:
1
1p
(m A)= V
M
oN x 0.000333
If 0.09V is measured, ion pump current is 30 µA.
If the power supply has been wired for positive output, the voltage
monitor signal is positive, and current signal is negative with respect to
chassis ground. If wired for negative, these polarities are reversed.
3. 7
Keypad Modes
Function mode
Numeric mode
3-10
Operation
The keyboard has two modes of operation, function and numeric.
The function mode is the normal mode. Whenever a key is pressed, its
function is executed. For example, if the key marked
STBY 1
is
pressed while in function mode, the DIGITEL goes to standby mode.
When a function requires numeric input, the keypad is placed in
numeric mode. The display shows a number with the left most 0
flashing. The flashing digit can be changed by pressing a numeric key.
For example, if
CURR 5
is pressed, the display would show 5000 with
the second digit flashing. After three digits are input, the first digit (a
five) flashes again indicating that it can be changed. In this way, it is
possible to correct a mistake by repeating the sequence When the
desired number is shown, press the
ENTER
key to enter the number.
