American Reliance PPS Series User manual

PPS SERIES
PROGRAMMABLE DC
POWER SUPPLY
OPERATION MANUAL
AMERICAN RELIANCE, INC.
11801 Goldring Road
Arcadia, CA 91006
Tel: [phone]

Table of Contents
ONE: INTRODUCTION
1.1 DESCRIFnON. 1
1.2 INSPECTION. 1
1.3 INCLUDED ITEMS. 1
1.4 CAUTIONS AND WARNINGS. 2
1.5 LOCATION AND COOLING. 2
1.6 GPIB INTERFACE CONNECTOR . 2
TWO: GETTING STARTED
2.1 UNIT FAMILIARIZATION. 3
2.2 LCD DISPLAY MESSAGES. 7
2.3 OUTPUT TERMINALS AND WIRES.. 8
THREE: OPERATING CBIARACTERISTICS AND CONFIGURATIONS
3.1 INTRODUCTION. 9
3.2 OPERATING RANGES. 9
3.3 REMOTE SENSE. 10
3.3.1 REMOTE SENSE CONFIGURATION. 10
3.3.2 REMOTE SENSE CHARACTERISTICS . 10
3.4 LOAD CONSIDERATION AND CONNECTING MULTIPLE LOADS . 11
3.5 PARALLEL OPERATION. 12
3.5.1 CV OPERATION . 12
3.5.2 CC OPERATION . 13
3.5.3 REMOTE SENSE CONFIGURAHON (Parallel Mode). 13
3.6 SERIES OPERATION. 13
3.6.1 CV OPERATION . 14
3.6.2 CC OPERATION . 14
3.6.3 REMOTE SENSE CONFIGURATION (Series Mode). 14
3.7 EXTERNAL ANALOG PROGRAMMING (PPS-1603 only) . 15

FOUR: LOCAL OPERATION
4.1 INTRODUCTION. 17
4.2 GENERAL INFORMATION. 17
4.3 SETTING VOLTAGE . 17
4.4 SETTING CURRENT . 18
4.5 SETTING & PROTECTION . 18
4.5.1 SETTING OVERVOLTAGE . 18
4.5.2 SETTING OVERCURRENT PROTECTION . 18
4.6 ENABLING/DISABLING OUTPUTS (CHI & CH2) . 18
4.7 RESETTING OUTPUT PARAMETERS. 19
4.8 TRACKING OPERATION (PPS-2322) 19
4.9 RANGE OPERATION (PPS-1326) 19
FIVE: REMOTE OPERATION
5.1 INTRODUCTION. 20
5.2 GPIB OPERATION . 21
5.2.1 GPIB INTERFACE FUNCTIONS . 21
5.2.2 ADDRESS SETTING OF GPIB INTERFACE .. 21
5.3 PROGRAMMING SYNTAX. 22
5.4 STATUS REPORTING . 23
5.5 PROGRAMMING THE POWER SUPPLY . 24
5.5.1 OUTPUT ON/OFF. 25
5.5.2 VOLTAGE PROGRAMMING. 25
5.5.3 OVERVOLTAGE PROGRAMMING (OVSET) . 25
5.5.4 CURRENT PROGRAMMING. 26
5.5.5 OVERCU'RRENT PROTECTION (OCP). 26
5.5.6 OTHER COMMON COMMANDS. 27
5.6 FUNDAMENTALS OF PROGRAMMING . 27

SIX: CALIBRATION
6.1 INTRODUCTION. 30
6.2 CALIBRATION CONFIGURATION . 30
6.3 LOCAL CALIBRATION. 31
6.4 REMOTB CALIBRATION. 33
6.5 CALIBRATION PROGRAM EXAMPLE. 33
SEVEN: USER BSAINTENANCE/SERVICE
7.1 FUSE REPLACEMENT. 34
7.2 IN CASE OF DIFFICULTIES. 34
7.3 WARRANTY INFORMATION. 35
7.4 SHIPPING INSTRUCTIONS. 36
EIGHT: APPENDICES
A. SPECIFICATIONS. 37
B. COMMAND SUMMARIES. 39
C. ERROR MESSAGES . 41
D. CALIBRATION PROGRAM EXAMPLE 42

TWO: GETTING STARTED
2.1 UNIT FAMILIARIZATION
Use the Illustrations of the power supplies In conjunction with the following descriptions to
familiarize yourself with the unit.
Figure A. Front Panel of PPS-1322/1302A
Figure B. Front Panel of PPS-1326

iMniE
Figure C. Front Panel of PPS-2322
Figure D. Front Panel of PPS-10710/1603

FRONT PANEL
NOTE: Most soft keys have two functions. The first function of the keys Is
function entry (l.e. VSET, ISET, OCP etc.). The second function for the soft
keys Is data entry (l.e. 0-9).
1. LCD Display
2. Power On/Off
3. Negative Terminal
4. Ground Terminal
t5. Positive Terminal
6. -S Terminal
7. +S Terminal
8. VSET (7)
9. ISET (8)
10. STAT (9)
-Displays all functions and operating characteristics. A detailed
listing of descriptions Is presented in section 2.2.
-Powers on the unit.
-Negative output terminal.
-Ground output terminal.
-Positive output terminal.
-Negative remote sense terminal.
-Positive remote sense terminal.
-Output control key used to display or alter the present voltage
setting. Numeric entry key for number seven.
-Output control key used to display or alter the present current
setting. Numeric entry key for number eight.
-Displays present status of LCD display (applicable only for the
PPS-2322). Numeric entry key for number nine.
11. CLEAR
12. OVSET (4)
13. OCP (5)
-Used in conjunction with the numeric entry keys to clear partially
set commands. Also returns unit to the metering mode.
-Output control key used to display or alter the present
overvoltage trip setting. Numeric entry key for number four.
-Mode control key which toggles the OCP on or off. When enabled,
the "OCP" Is displayed. Numeric entry key for number five.
14. LCL (6)
15. OUTPUT (ON/OFF)
16. TRK (1)
17. RANGE (2)
-An operation mode control key which returns the supply to local
mode. Numeric entry key for number six.
-Mode control key which toggles the output on or off when the
output Is disabled, the LCD displays "OUTPUT OFF." (The model
PPS-2322 has two output enable/disable keys signified by "CHI"
and "CH2.'j
-Mode control key which toggles the tracking mode on or off.
When enabled, the LCD displays 'TRK." (applicable only for the
PPS-2322). Numeric entry key for number one.
-Mode control key which selects the operating range. The low
range (normal) Is 32 volts, 3 amps; the high range (extended) is
16 volts, 6 amps. When high range Is active, the LCD displays
5

"HI," when low range active, the LCD displays "LO" (applicable
only for the PPS-1326). Numeric entry key for number two.
18. ADDR (3) -System control key which provides a means to view or alter the
GPIB address. Addresses available are 0-30. Numeric entry key
for number three.
19. "0" -Numeric entry key for "0."
20. -Decimal point key.
21. ENTER -Enters the values on the display for the specified function and
returns the display to metering mode.
22. CH2 (ON/OFF) -Mode control key which toggles the channel 2 output on or off.
When output disabled, the LCD displays, "OUTPUT OFF'
(applicable only for the PPS-2322).
23. Arrow Key -A key which toggles the display message between two channels
(applicable only for the PPS-2322).
Figure E. Rear Panel
REAR PANEL
24. Ventilation Fan -Used to exhaust warm air from unit.
25. GPIB Interface -24 pin parallel GPIB Interface connector.
6

26. Voltage Selector
27. Fuseholder
28. AC receptacle
29. Negative Terminal (-)
30. Positive Ter minal (+)
31. -S
-Selects voltage of either 115 or 230 VAC, -10% ~ +6%, 50/60Hz.
-Fuseholder for AC line.
-AC plug for power cord.
-Negative rear screw terminal output for hard wiring.
-Positive rear screw terminal output for hard wiring.
-Negative rear screw terminal for rerr ate sense output. Enables
hard wiring.
32. +S -Positive rear screw terminal for remote sense output. Enables
hard wiring.
33. Ground Terminal -ground rear screw terminal.
NOTE:
(1) The rear panel configuration Is Identical on all power supplies. However, the
PPS'2322 has an additional terminal strip for hard wiring the second channel.
(2) The PPS-1603 has an external programming input terminal located at the rear
of the supply. Please refer to section 3.7 for further information.
2.2 LCD DISPLAY BCESSAGES
The LCD display current output voltage and current and the following display messages. These
messages are viewed in either local or remote mode.
LOC -The supply is operating in local mode.
LWL -Local operation with local lockout.
REM -The supply is operating under remote mode.
RWL -Remote operation with local lockout.
CV -The supply Is operating under constant voltage mode.
CC -The supply is operating under constant current mode.
OV -The overvoltage circuit has tripped and disabled the output.
OC -The overcurrent circuit has tripped and disabled the output.
OCP -The overcurrent protection circuit is enabled.
TRK -The suppfy is operating in tracking mode. Applicable only for the PPS-2322.
HI -The supply Is operating In the high range. Applicable only for the PPS-1326.
LO -The supply is operating In the low range. Applicable only for the PPS-1326.
OUT OF FLANGE -Value entered is out of range.
7

2.3 OUTPUT TERMINALS AND WIRES
All four models possess terminal blocks on the back panel. The terminals in the rear Include
positive and negative outputs, positive and negative remote sense outputs and ground.
NOTE:
The power supply Is set at the factory for local sense operation (l.e. the +S and -S
terminals are strapped to the "+" and terminals by a shorting plug at the rear
terminal block). When operating In remote sense mode, remove the shorting plugs and
refer to section 3.3 for remote sense operation.
Additionally, all four models have positive, negative and ground terminals in the front of the
unit. However, only the PPS-1326 and PPS-10710 have remote sense terminals via the front
panel. Remote sense Is discussed In detail In section 3.3. A brief definition of remote sense
Is a measurement of voltage at the load rather than at the output terminals.
Local connections are made to the "+,” and terminals of the power supply. Remember to
connect only terminated loads. Additionally, wrap and bundle wires to decrease coupling.
In order to sufficiently handle current, the proper wire size must be selected. Select a wire size
which sufficiently carries the current without overheating. Other factors to be considered are
the voltage drop and conductor temperature.
The following table lists current carrying capacity of various wire sizes. Additionally, one may
refer to the NEC 1987 Handbook.
TABLE 1:
Stranded Copper Wire Ampacity and Resistivity.
Amnacltv Per Wire lAmnsl
Wire Size
fAWGI
2 Wire Bundle
4 Wire Bundle
(ohm/ftl
Resistivity
20
7.8
6.9
0.0102
18
14.5
12.8
0.0064
16
18.2
16.1
0.0040
14
29.3
25.9
0.0025
12
37.6 33.2 0.0016
8

THREE: OPERATING CHARACTERISTICS AND CONFIGURATIONS
3.1 INTRODUCTION
These sections contain Information on operating characteristics and how to configure the PPS
Series. Sections 3.2 through 3.4 consider the power supplies operating ranges, remote sense
operation and considerations when connecting loads.
The latter half of the chapter deals with connecting power supplies In parallel and series mode
for CC and CV operation.
3.2 OPERATING RANGES
All power supplies operate in either constant voltage (CV) or constant current (CC), over the
rated output . Their respective voltage and current operating locus (figure F) are found in
operating quadrants for dll four models. The power supply acts as a constant voltage source
for comparatively large values of load resistance and as a current source for comparatively
small values of load resistance. The automatic crossover or transition between these two
modes of operations occurs at a critical stage or "crossover" value of load resistance; =
E,/I,, where E, is front panel voltage setting and I, front panel current setting.
The following are the operating quadrants (current -vs- voltage) of the power supplies.
PPS-1322/1302A
PPS-1326
'i
32V +
60V +
V
A
I
PPS-2322
PPS-1603 PPS-10710
Figure F. Operating Quadrants

3.3
REMOTE SENSE
When the supply Is locally strapped for local sensing (normal operation), an unavoidable
voltage drop is developed In the load leads and this adds to Its voltage regulation. By
connecting the supply for voltage remote sensing, as shown In figure G, voltage Is sensed at
the load rather ^an at the output terminals. This allows the supply to automatically
compensate for voltage drop In the load leads and Improve regulation. In remote sensing, the
VOITT? query and the front panel meter monitor load voltage at the sensing points.
When the supply Is connected for remote sensing, the OVP circuit senses at the main output
terminal and not at the sense points. The voltage sensed by the OVP circuit could be
significantly higher than the voltage being regulated at the load. Therefore, set OVP trip voltage
accordingly.
3.3.1 REMOTE SENSE CONFIGURATION
Turn off the power supply before modifying any connections on the rear panel terminal block.
Configure the unit for remote sensing by first disconnecting the shortlrig plugs between the
sense and load terminals. Connect the load and sense leads to the load as In figure G. Bear
In mind that sense and load leads should be as short as possible. Additionally, the sense and
load leads resistance should be no greater than 0.5 ohm/lead, and the voltage drop should
be no greater than 0.5V/lead.
Figure G. Remote Sense Configuration
3,3.2 REMOTE SENSE CHARACTERISTICS
CV REGULATION: The CV load effect specification applies to the rear terminal of the supply.
When remote sensing, add 0.2mV {PPS-1322 and PPS-2322), 0.7mV (PPS-1326), or 1.5mV
(PPS-10710) to the load effect specification for each IV drop In the negative load lead. For
example. If the voltage drop on the negative load lead of a PPS-1322 Is 300mV, add 0.3 x
0.2mV to the CV load effect specification.
10

OUTPUT NOISE: Any noise picked up on the sense leads will appear at the supply’s output
and may adversely affect CV load regulation. Twist the sense leads to minimize the pickup of
external noise and run them parallel and close to the load leads. In noisy environments. It
may be necessary to shield the sense leads. Ground the shield at the power supply end only.
Do not use the shield as one of the sensing conductors.
STABILITY: When the supply Is connected for remote sensing. It Is possible for the impedance
of the load wires and the capacitance of the load to form a filter, which will become part of
the supply’s CV feedback loop. The extra phase shift created by this filter can degrade the
supply’s stability and can result in poor transient response performance. In extreme cases, it
can cause oscillations.
It Is difficult to state simple rules defining the conditions under which this can occur, and
which corrective action to take. A certain amount of trial and error may be called for. Two
guidelines which are almost always valid are:
a. Keep the leads as short as possible.
b. Twist the load leads together to minimize inductance.
In most circumstances, once these two guidelines are followed, problems associated with the
load lead inductance are eliminated. This leaves the load lead resistance and load capacitance
as the major cause of the reduced stability. In this case, you may obtain further improvement
to the stability by:
a. Keeping the load capacitance as small as possible.
b. Increasing the diameter of the load lead to reduce resistance.
If heavier gauge load leads { #10 or greater ) are used, circumstances may arise when the load
lead inductance and the load capacitance can form an underdamped filter. This filter
occasionally has the effect of destabilizing phase response. In this case, the above steps can
worsen stability since they will reduce damping in the system.
3.4 LOAD CONSIDERATION AND CONNECTING MULTIPLE LOADS
When the supply Is in local sensing mode and you are connecting multiple loads to the
output, connect each load to the output terminal using separate load leads. This minimizes
mutual coupling effects and takes full advantages of the supply’s low output resistance. Each
pair of wires should be as short as possible and twisted or bundled to reduce lead inductance
and noise pickup.
If cabling considerations require the use of distribution terminals that are located remotely
from the supply, connect the power supply output terminals to the remote distribution
terminals by a pair of twisted or bundled wires. Connect each load to the distribution
terminals separately. Remote voltage sensing is recommended in these circumstances. Sense
either at the remote distribution terminals or, if one load is more sensitive than the others,
directly at the critical load.
OUTPUT ISOLATION: The output of the power supply is Isolated from earth ground. Either
output terminal may be grounded, or an external source of voltage may be connected between
either output and ground. However, both output terminals must be kept within +/-240Vdc of
ground. 'ITils includes the output voltage. An earth ground terminal is provided on the rear
panel terminal block.
Each of the power supplies will operate accordingly to the various types of loads connected
to the output.

CAPACITANCE LOADING; In normal conditions, the supply will be stable for almost any size
load capacitance (for remote sense stability considerations). However, large load capacitance
may cause ringing In the supply’s transient response. It Is even possible that certain
combinations of capacitance and ESR (equivalent series resistance) will result In Instability.
If this Is the case, the solution is to Increase or decrease total load capacitance. In addition,
the overvoltage protection SCR crowbar circuit has been designed to discharge capacitance up
to a certain limit. These limits are:
model PPS-1322 : 3000uf
model PPS-1326 : 3000uf (high range), SOOOuf (low range)
model PPS-2322 : 3000uf for both outputs
model PPS-10710: 3000uf
If load capacitance approaches these limits. It Is recommended to not Intentionally trip the
OVP and discharge the capacitance through the SCR crowbar as part of standard testing
procedure.
3.5 PARALLEL OPERATION
NOTE: Power supplies equipped with SCR crowbars should not be used In series or parallel
with each other unless a master-slave Intercormectlon Is employed and their crowbars
Interlock.
Greater current capability can be achieved by cormecttng outputs In parallel. However, only
power supplies which have equivalent voltage and current output ratings may be
connected in parallel. Otherwise, damage to the unit may result.
A typical coimectlon Is shown In figure H through the back of a PPS-2322 In local sensing.
All leads are kept as short as possible and are bundled together. Second, cormect remote
sense terminals to compensate for the voltage drop in the Interconnecting load leads. Lastly,
the CV and CC operations have Identical setups.
LOAD
Figure H. Parallel Configuration
3.5.1 CV OPERATION
Although both outputs operate Independently of each other In CV operation, one of the outputs
must dominate (control) over the other. Additionally, the dominant output must operate In CV
12

mode, while the other output may operate In CC mode.
As an example of this operation, let’s assume In figure H. that output two operates In CC
mode and output one operates in CV mode. Perform the following steps:
1. Set output two to the maximum output voltage of desired range.
2. Set output one to the desired operating voltage.
The voltage of output one controls the voltage across the load. The output currents are
algebraic sums of the Individual outputs.
3.5.2 CC OPERATION
The CC operation Is similar In many ways to the CV operation, except that the output
current must also be set. To obtain CC operation, perform the following steps:
1. Program both output voltages to the desired operating voltage.
2. Program output one to one-half the desired operating current.
3. Program output two to one-half the desired operating current.
Both outputs operate In CC mode.
3.5.3 REMOTE SENSING CONFIGURATION (Parallel Mode)
The following figure 1 Illustrates the configuration for Remote Sensing In Parallel Operation.
‘4nir
Ciurio*
o
o nn o
TTITIJ
Figure I. Remote Sense, Parallel Mode
3.6 SERIES OPERATION
NOTE: Power supplies equipped with SCR crowbars should not be used In series or parallel
with each other unless a master-slave Interconnection Is employed and their crowbars
interlock.
13

Greater output voltage capability can be obtained by connecting outputs in series. A note of
caution, since current is the same in each element of a series circuit, both outputs need
identical rated currents. If this is not followed, excessive current may be forced into one
of the outputs and cause a failure.
Figure J illustrates the Series configuration on a PPS-2322.
Figure J. Series Configuration
3.6.1 CV OPERATION
In CV operation, first program the current of both outputs to the desired value. Secondly,
program the desired operating voltage to equal the sum of the output voltages.
3.6.2 CC OPERATION
In CC operation, one output will operate in CV mode, the other in CC mode. To obtain this
operation, perform the following;
1. Program the two output currents to the desired operating current.
2. Program output one to one-half the desired operating voltage.
3. Program output two to one-half the desired operating voltage.
At load levels less than one half the total voltage limit, the output that was originally in CC
mode, stays in CC mode.
At load voltages greater than one-half the total voltage limit, the output that was originally In
CC mode, changes to CV mode. The secondaiy output will regulate the current In CC mode
and provide the necessary voltage.
3.6.3 R EMOTE SENSE CONFIGURATION (Series Mode)
The following figure K Illustrates the configuration for Remote Sensing In Series Operation.
14

Figure K. Series Conflguration with Remote Sense
3.7 External Analog Programming (PPS-1603 only)
The voltage and current outputs of the PPS-1603 can be programmed by an external analog
voltage. The outputs are linearly proportioned to an external input voltage from 0 to 10 volts.
The external analog programming mode is activated by setting these parameters via the front
panel or GPIB bus, VSET to OV, ISET to a proper value for CV operation, or setting ISETT to
OA and VSET to a proper value for CC operation.
To control the output voltage with the analog programming mode requires the following
procedure, apply the external 0 to lOV source (Vv-pgm) between Vp (positive), and
(common) terminals. These Input terminals are located at the rear of the PPS-1603, see
figure L.
The control output voltage is;
Vout = Vv-pgm * (Rated Maximum Output Voltage/ 10)
To control the output current with the analog programming mode requires the following
procedure, apply the external 0 to lOV source (Vi-pgm) between Ip (positive) and^I (common)
terminals, see figure L.
The control output current Is:
lout = Vi-pgm * (Rated Maximum output current / 10)
To control both voltage and current simultaneously In the external programming method
requires that the user apply two senerate Isolated 0 to lOV supplies.
15

Normally Vp, -^V, Ip, and are strapped by steel plates. Do not remove the steel plates
without activating the external analog programming mode.
NOTE: The tV and il terminals are at a negative sense potential, with this in
mind do not connect them to any other terminal on the rear panel. This
precaution prevents your power supply from overheating or permanently damaging
the unit.
Figure L. Rear Panel of PPS-1603
16

FOUR: LOCAL OPERATION
4.1 INTRODUCTION
These sections contain Information on how to locally program the PPS Series. Upon powering
up, the power supplies default to local mode of operation. Local operation Is signified by
"LOC" on the LCD. When "LOC" Is In effect, all front panel keys may be used to control the
power supply.
NOTE:
1. The PPS series of power supplies and their operations are Identical. However, two
of the supplies provide more functions (l.e. PPS-2322 has dual outputs and PPS-1326
has two output operating ranges) which may slightly alter or add to programming
conditions. TTierefore, refer to approplate sections for these operations.
2. The PPS-1322 and PPS-10710 are Identical hi operation. However their outputs
differ.
All operations performed In local mode, may also be performed In remote mode. The unit
signifies remote operation by displaying "REM," on the LCD.
4.2 GENERAL INFORMATION
1. The power supplies are able to directly accept programming values of voltage, current and
overvoltage. "When a valid Input Is made, the unit will round off the value to the nearest
multiple of the resolution (typically lOmV and ImAl." If a non-valld Input Is made, the
unit will display "OUT OF RANGE." and return to previous set values.
2. The actual operation of programming the voltage and current values Is simple. Simply, press
any of the functional keys and the display shows the present value. To change this value,
simply use the numeric keys to enter a value. If an error is made, press the clear key
and then reselect the parameter that was to be modified. Once the final value is set,
press the "ENTER" key. Pressing the "ENTER" key will; display the actual value. Initiate the
function, and return the unit to metering mode. If a user wishes to recall a setting, press the
function key pertaining to the operation. For example, to recall a set voltage, press "VSET."
Press "ENTER" to return unit to metering mode.
3. The PPS-2322 has two outputs (channels) and these may be alternately viewed via the
"cursor" key. In order to program the output parameters for each output channel, first toggle
the "cursor" key to the respective channel and then observe the following guidelines.
4.3 SETTING VOLTAGE
To locally program the voltage (VSET), press "VSEIT', enter the value and press "ENTER." For
example, if one wished to set a voltage of 3.99, press:
VSET
3
•
9
9 ENTER
the LCD displays 3.99 and the unit returns to metering mode.

4.4 S ETTING CURRENT
To locally program the current (ISET), press "ISET," enter the value and press "ENTER" For
example. If one wished to set a current of 1.69 amps, press:
ISET
1
6
9
ENTER
the LCD displays 1.69 and the unit returns to metering mode.
4.5 S ETTING AND PROTECTION
The power supplies have overvoltage setting protection (OVSET) and overcurrent protection
(OCP) features to guard against abnormal operating conditions. When either of these two
Inunctions are tripped, the unit disables the output and the LCD displays either "OV."
( overvoltage has tripped ) or "OC." ( overcurrent has tripped ).
<NOTE;> If using remote sense, take Into consideration the voltage drop of the leads since
overvoltage Is measured from the output terminals.
4.5.1 SETTING OVERVOLTAGE
To locally program the "OVSET," press "OVSETT," enter the value and press "ENTER." For
example, to program an overvoltage value of 4.50V, press:
OVSET
4 5 0
ENTER
4.5.2 SETTING OVERCURRENT PROTECTION
If the output current exceeds the maximum current rating of the power supply when the OCP
Is on, the unit with reduce the output current to zero.
To locally enable the "OCP," press the "OCP," key. The "OCP" armunclator Is displayed on the
LCD. To disable the "OCP," press the "OCP" key a second time and the annunciator Is
removed from the LCD display.
4.6 E NABLING/biSABLING OUTPUTS
All models of the PPS series have the ability to disable their outputs and have their values
modlfled. When the modification has been completed, one can enable the power supply to
operate at the new values.
The output Is "Enabled/Dlsabled by toggling the "OUTPUT' (ON/OFF) key. The model PPS-
2322 outputs are enabled/dlsabled by toggling the CHI (ON/OFF) or CH2 (ON/OFF) keys
respectively.
18