MKS 900 Series User manual

PDR 900
Series 900 vacuum controller
RS232 / RS485
Operation Manual
P/N: 100017303
PDR900-12, Operation Manual
Revision: A, November 2008

Extent of the Warranty
MKS Instruments, Inc., HPS™ Products Inc. and MKS Denmark ApS warrants the PDR900 Vacuum Controller and its accessories to be free from defects
in materials and workmanship for one (1) year from the date of shipment by HPS™ or authorized representative to the original purchaser (PURCHASER).
Any product or parts of the product repaired or replaced by HPS™ under this warranty are warranted only for the remaining unexpired part of its one (1)
year original warranty period. After expiration of the applicable warranty period, the PURCHASER shall be charged HPS™’ current prices for parts and
labor, plus any transportation for any repairs or replacement.
ALL EXPRESS AND IMPLIED WARRANTIES, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE, ARE LIMITED TO THE WARRANTY PERIOD. NO WARRANTIES, EXPRESS OR IMPLIED, WILL APPLY AFTER THIS PERIOD.
Warranty Service
The obligations of HPS™ under this warranty shall be at its option: (1) to repair, replace, or adjust the product so that it meets applicable product
specifications published by HPS™ or (2) to refund the purchase price.
What Is Not Covered
The product is subject to above terms only if located in the country of the seller from whom the product was purchased. The above warranties do not apply
to:
I. Damages or malfunctions due to failure to provide reasonable and necessary maintenance in accordance with HPS™ operating instructions.
II. Damages or malfunctions due to chemical or electrolytic influences or use of the product in working environments outside the specification.
III. Fuses and all expendable items which by their nature or limited lifetime may not function for a year. If such items fail to give reasonable service for a
reasonable period of time within the warranty period of the product; they will, at the option of HPS™, be repaired or replaced.
IV. Defects or damages caused by modifications and repairs effected by the original PURCHASER or third parties not authorized in the manual.
Condition of Returned Products
HPSTM will not accept for repair, replacement, or credit any product which is asserted to be defective by the PURCHASER, or any product for which paid or
unpaid service is desired, if the product is contaminated with potentially corrosive, reactive, harmful, or radioactive materials, gases, or chemicals.
When products are used with toxic chemicals, or in an atmosphere that is dangerous to the health of humans, or is environmentally unsafe, it is the
responsibility of the PURCHASER to have the product cleaned by an independent agency skilled and approved in the handling and cleaning of
contaminated materials before the product will be accepted by HPSTM for repair and/or replacement.
In the course of implementing this policy, HPSTM Customer Service Personnel may inquire of the PURCHASER whether the product has been contaminated
with or exposed to potentially corrosive, reactive, harmful, or radioactive materials, gases, or chemicals when the PURCHASER requests a return
authorization. Notwithstanding such inquiries, it is the responsibility of the PURCHASER to ensure that no products are returned to HPS™ which have been
contaminated in the aforementioned manner.
Other Rights and Remedies
I. These remedies are exclusive. HPS™ SHALL NOT BE LIABLE FOR CONSEQUENTIAL DAMAGES, FOR ANTICIPATED OR LOST PROFITS,
INCIDENTAL DAMAGES OR LOSS OF TIME, OR OTHER LOSSES INCURRED BY THE PURCHASER OR BY ANY THIRD PARTY IN CONNECTION
WITH
THE PRODUCT COVERED BY THIS WARRANTY, OR OTHERWISE. Some states do not allow exclusion or limitation of incidental or consequential
damage or do not allow the limitation on how long an implied warranty lasts. If such laws apply, the limitations or exclusions expressed herein may not
apply to PURCHASER.
II. Unless otherwise explicitly agreed in writing, it is understood that these are the only written warranties given by HPS™. Any statements made by any
persons, including representatives of HPS™, which are inconsistent or in conflict with the terms of the warranty shall not be binding on HPSTM unless
reduced to writing and approved by an authorized officer of HPS™.
III. This warranty gives PURCHASER specific legal rights, and PURCHASER may also have other rights which vary from state to state.
IV. For HPS™ products sold outside of the U.S., contact your MKS representative for warranty information and service.
Warranty Performance
To obtain warranty satisfaction, contact the following:
US & ASIA:
MKS Instruments, Inc., HPS™ Products, Inc., 5330 Sterling Drive, Boulder, CO 80301, USA, Phone: [phone].
EUROPE:
MKS Denmark ApS, Ndr. Strandvej 119G, DK3150 Hellebaek, Denmark, Phone: [phone], E-mail: [e-mail]
Part number: PDR900-12-_ _ _ _ _ _ _ _ _
Serial number: _ _ _ _ _ _ _ _ _ _ _ _ _ _
Please fill in these numbers and have them readily available when calling for service or additional
information. The part number can be found on your packing slip, and both the part number and serial
number are located on the side of the housing.
© 2006 MKS Instruments. All rights reserved.
Trademarks used in this manual: HPS™, MicroPirani™, DualTrans™ and Quattro™ are trademarks of MKS Instruments Inc. Windows®
is a trademark of Microsoft Corporation

Table of Contents
Safety information.............................................................................................................................................. 2
Symbols used:............................................................................................................................................... 2
Unpacking.......................................................................................................................................................... 3
Transducers and cables ................................................................................................................................ 3
Controller installation ......................................................................................................................................... 3
Transducer installation....................................................................................................................................... 3
Description......................................................................................................................................................... 4
Series 900 transducers...................................................................................................................................... 4
Rear panel & connections.................................................................................................................................. 6
Electrical Connections ....................................................................................................................................... 7
Transducer analog output ............................................................................................................................. 7
Serial user interface ...................................................................................................................................... 7
Setpoint relay ................................................................................................................................................ 8
Front panel......................................................................................................................................................... 9
Menu interface ................................................................................................................................................. 10
View menu ....................................................................................................................................................... 10
Data logger tool ............................................................................................................................................... 11
Leak detector tool ............................................................................................................................................ 11
Edit menu......................................................................................................................................................... 12
Set point........................................................................................................................................................... 12
Alarm ............................................................................................................................................................ 12
Analog output................................................................................................................................................... 13
Setup menu ..................................................................................................................................................... 13
Display setup ................................................................................................................................................... 13
Unit setup......................................................................................................................................................... 13
Calibration........................................................................................................................................................ 13
User communication ........................................................................................................................................ 14
Setup of user interface ................................................................................................................................ 14
Transducer Communication ........................................................................................................................ 14
Command Set ............................................................................................................................................. 15
Maintenance .................................................................................................................................................... 17
Changing fuse.................................................................................................................................................. 17
Disposal ........................................................................................................................................................... 17
Menu structure................................................................................................................................................. 18
Specifications................................................................................................................................................... 22
Dimensions ...................................................................................................................................................... 22
Accessories and replacement part numbers ................................................................................................... 23
Transducer cables....................................................................................................................................... 25
Controller connectors & cables ................................................................................................................... 25
Mounting hardware...................................................................................................................................... 25
Power cords................................................................................................................................................. 25
Calibration certificate................................................................................................................................... 25
CE Declaration of Conformity .......................................................................................................................... 26
Index ............................................................................................................................................................ 28

For more information contact:
MKS Denmark ApS
Ndr. Strandvej 119G
DK-3150 Hellebæk
Denmark
Tel: [phone] – Fax: [phone]
Email: mksdenma[email protected]
MKS Instruments, HPS Products
5330 Sterling Dr.
CO-80301 Boulder
USA
Tel: [phone] - Fax: [phone]

PDR900 Operation manual 2
Safety information:
Symbols used:
The first two symbols below are used throughout this manual to further define the safety concerns associated
with the product. The last two symbols identify other information in this manual that is essential or useful in
achieving optimal performance from the PDR900.
Caution:
Risk of electrical shock. Failure to read message could result in
personal injury
Caution:
Refer to manual. Failure to read message could result in personal
injury or serious damage to the equipment or both.
Failure to read message could result in damage to the equipment.
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Calls attention to important procedures, practices or conditions.
General safety information
The safety instructions should always be followed during installation and operation of the PDR900 controller.
Otherwise, there is danger for electric shock and/or fire. Safety and installation instructions must be followed
for continued compliance to low-voltage directive EN61010-1 (IEC1010-1). Pass safety information to all
users.
Safety Precautions:
Grounding. The PDR900 controller must always be properly grounded. Be sure that the
ac power line is grounded and use only the delivered 3 channel power cord or other
approved power cord. Before connecting any other inputs, be sure to connect the ac
power cord. Disconnect all other cables before removing the ac power cord.
Fuse change. If fuse change is required, remove all other inputs and finally ac power line.
Use only approved 5x20mm, 250Vac, 500mA, T.
Explosive Environments. Do not use the PDR900 in presence of flammable gases or
other explosive environments.
Rack installation. When installed in rack the ac power should be controlled from a central
power supply.
Service and Repair. Do not substitute parts or modify instrument. Do not install
substituted parts or perform any unauthorized modification to the instrument. Return the
instrument to an MKS Calibration and Service Center for service and repair to ensure all
of the safety features are maintained.
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CE marking The PDR900 complies with following European standards for CE
marking. EN61326-1, Electromagnetic compatibility
EN 61010 (IEC 1010-1), Low voltage directive.

PDR900 Operation manual 3
Unpacking
Before unpacking your PDR900 controller, check all surfaces of the packing material for shipping damage.
Please be sure that your PDR900 package contains these items:
Part number Description PDR900-12-US
PDR900-12-EU PDR900-12-UK
PDR900-12 Controller, RS232/485 1 1 1
100013463 Power cord US 1 - -
100013464 Power cord Schuko - 1 -
100013465 Power cord UK - - 1
100013726 Spare fuse 5x20mm, 500mA, T (1) 1 1 1
100010757 Relay connector 3 3 3
100013690 Mounting kit 1 1 1
100017303 Operating manual, English 1 1 1
(1) Spare fuse is integrated in the fuse holder on the rear panel.
If any items are missing, please call MKS Customer Service at [phone] or [phone] or your local
MKS sales office or distributor. Inspect for visible damage. If found, notify the carrier immediately.
Transducers and cables
Transducer and transducer cable are ordered separately. Use only the PDR900 cables listed below for
transducer connection. The PDR900 is compatible with following transducers:
RS232 Transducer Cable 10 ft. / 3 m. (2) RS485 Transducer Cable 10 ft. / 3 m. (2)
P/N Description 100013613 100013620 100013740 100013671 100013664 100013703
901P Loadlock - X - X - -
902 Piezo X - - - X -
909AR Ionization - - X - - X
909 Ionization - - - - - X
910 DualTrans™ - X - X - -
925C MicroPirani™ X - - - X -
925 MicroPirani™ - X - X - -
971 UniMag - X - X - -
972 DualMag - X - X - -
973 TriMag - X - X - -
974 QuadMag - X - X - -
979 ATV - X - X - -
999 Quattro™ - X - X - -
(2) Other cable lengths are available. See Accessory and Replacement part number page 47-48 for ordering information.
Controller installation
Do not use or install the PDR900 where following conditions occur:
- Temperatures lower than 0 oC or higher than 40 oC
- Corrosive or explosive gases
- Direct sunlight
- Altitude higher than 2000 m
The PDR900 can either be built into a rack panel or be used as a free standing unit. For built-in applications
the panel cut should be 92x92 mm. A mounting kit is included for the purpose of mounting the unit in a panel.
For 19” rack mounting (3U height) a ¼ rack (21HP) mounting panel is available. See Accessory and
Replacement part number page 47-48 for ordering information.
The IP classification according to IEC 60529 is IP30 when used as a free standing unit.
Transducer installation
Please refer to the transducer operation manual for detailed information on how to install
the transducer.

PDR900 Operation manual 4
Description
The PDR900 is a stand alone single channel power supply and display
unit for use with the Series 900 transducers. The instrument provides
easy readout of pressure measurement and can also be used for setup
and configuration of transducer parameters.
The user interface gives a quick and easy access to all settings and
parameters through logically arranged menus.
The PDR900 is not only a readout and power supply unit; it also provides
diagnostic tools like a real time data logger, leak detector tool and audio
alarm.
The controller communicates with the connected transducer via the digital RS232 or RS485 interface. The
digital communication between controller and transducer eliminates analog measurement noise known from
analog gauges and controllers.
Series 900 transducers
The HPS Series 900 vacuum transducers are a complete
suite of microprocessor based, stand alone gauges, offering a
wide pressure measurement range from above atmosphere to
ultra high vacuum. Designed for system integration, the
transducers offer both analog and digital communication. All
transducers have integrated setpoint relay for process
controlling.
The transducers incorporate MEMS (Micro Electro-
Mechanical systems) based technologies, including
MicroPirani™ and Piezo sensors, combined with Mini Ion BA
technology resulting in a broad product offering for a wide
range of customer applications.
901P Loadlock transducer
The 901P is a unique patented transducer
designed specifically for the loadlock
environment. It provides both vacuum
pressure measurement and atmospheric
switching capabilities.
902 Piezo
The 902 Piezo provides an absolute
measurement that is independent of gas
type.
909 Mini-Ion
The 909 offers pressure measurement from UHV to 1×10-2 Torr and it’s based on hot cathode ionization
sensor.
910 DualTrans™
The 910 DualTrans™ is a dual sensor transducer, combining absolute piezo sensor and MicroPirani™
sensor. The transducer measures over pressure down to 1×10-5 Torr.
925C MicroPirani™
The MicroPirani provides a measuring range from 1×10-5 Torr to atmosphere with 1 or 3 integrated setpoint
relays for process controlling.
971 UniMag™
The 971 UniMag™ is a Inverted Magnitron transducer. The transducer provides a measuring range from
1×10-8 Torr to 1×10-2 Torr.
972 DualMag™
The 972 DualMag™ is a Inverted Magnitron transducer combined with a MicroPirani™ sensor. The
transducer provides a measuring range from 1×10-8 Torr to atmosphere.
10
-10
10
-9
10
-8
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
+4
110 100 1000
Pressure in Torr
901P Loadlock
910 DualTrans
925 MicroPirani
902 Piezo
971 UniMag
972 DualMag
909 MiniIon
979 ATV
999 Quattro
973 Tri Mag
974 QuadMag

PDR900 Operation manual 5
973 TriMag™
The 973 TriMag™ is a Inverted Magnitron transducer combined with a MicroPirani™ sensor and an absolute
piezo sensor. The transducer provides a measuring range from 1×10-8 Torr to atmosphere.
974 QuadMag™
The 974 QuadMag™ is a Inverted Magnitron transducer combined with a MicroPirani™ sensor and an
differential piezo sensor. The transducer provides a measuring range from 1×10-8 Torr to atmosphere.
979 ATV
The 979 combines the MicroPirani and the Mini ion BA gauge and provide a wide measuring range from
UHV to atmosphere.
999 Quattro™
The 999 Quattro™ is based on three sensor types with the functionally of four sensors, providing a pressure
measurement from UHV to 1000 Torr, combined with atmospheric switching capabilities.

PDR900 Operation manual 6
Rear panel & connections
1. Power on / off switch
Main supply on / off switch
2. Fuse holder
For main fuse change refer to page 16
3. Power in
Main supply voltage 100-240Vac, 50-60Hz,
25W
4. Analog Out (8 pin DIN female)
1. Transducer analog out+
2. Transducer analog out-
8. Chassis (Ground)
5. Communication (9 pin DSUB male)
2. RS232 Transmit / RS485-
3. RS232 Receive / RS485+
5. Ground
6. Transducer (15 pin HD DSUB female)
1. RS485- / RS232 TXD
2. RS485+ / RS232 RXD
3. +24 VDC power output
4. Power Ground
5. Analog in+
6. Analog in -
7. Setpoint relay 1 control (Ground)
8. Setpoint relay 1 control
9. Not connected
10. Not connected
11. Setpoint relay 2 control
12. Setpoint relay 2 control (Ground)
13. Not connected
14. Setpoint relay 3 control
15. Setpoint relay 3 control (Ground)
7. Setpoint Relay (screw terminal connector)
1. Normally Open contact
2. Normally Closed contact
3. Common contact
12
3

PDR900 Operation manual 7
Electrical Connections
Transducer analog output
The analog voltage output can be used for connection to external analog measuring equipment for pressure
reading and data logging. The analog output is provided by the transducer measurement circuit. The analog
out voltage vs. pressure varies from transducer type. For specific transducer voltage levels refer to
transducer operation manual.
The analog output must be connected to a differential input voltmeter or an analog to digital (A/D) converter
with a differential input in a system controller.
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Do not connect the negative side of the analog output (pin 2) to the chassis / ground
(pin 4) or to any other ground. Measurement errors in the output voltage may be seen
due to the voltage drop from this current loop flow. The longer the cable, the worse
the error will be.
If the analog output is improperly connected, shorted to ground or heavily loaded, the
pressure transducer performance and consequently pressure reading can be affected.
Analog output connector and cables are available as accessories. Refer to Accessory and replacement part
number page 23-25.
Serial user interface
The PDR900 is as standard supplied with RS232 and RS485 user interface. The user interface allows
change of transducer and controller parameters as well.
The serial interface uses following format: 8 data bit, 1 stop bit, no parity bit.
RS232 user interface
The PDR900 is DCE (data communication equipment) and
can be connected via straight cable to DTE (data terminal
equipment) typical a PC.
The serial communication does not use hardware handshake.
RS485 user interface
RS485 is a network communication system that enables the
user to communicate with several units on the same
communication line.
RS485 is a balanced communication system. There are 2
wires, other than ground, that are used to transmit the digital
signal. The PDR900 uses half duplex communication.
At high communication baud rates and when using long cable
runs a termination resistor of typical 120 Ohm should be
connected between pin 2 and 3 at the PDR900 RS485
connector.
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Always use high quality shielded data cables for serial communication.
See also Accessory and replacement part number page 23-25.

PDR900 Operation manual 8
Setpoint relay
The PDR900 has 3 mechanical power relays that can be used for controlling external process equipment.
The power relays are controlled by the internal transducer relays and consequently only one power relay is
available when using single setpoint transducers like the 902 and 925C. Refer to the transducer and setpoint
relay table below.
The relay has closing and breaking contacts
and the contacts are rated for 250Vac, 4A,
resistive load.
For inductive loads such as solenoids, coils,
etc. refer to the graph for load reduction factor.
The graph can’t be used for electrical motors.
Wire sized from 0.5 to 1.5 mm2can be
mounted at the relay connector. 3 relay
connectors are included with the PDR900
controller. For spare connectors refer to
Accessories and replacement part number
page 47-48.
1. NO, Normally Open
2. NC, Normally Closed
3. Common
1
3
2
Do not connect any external sources to the transducer relays pins when using the
transducer together with the PDR900. Always use the PDR900 relay outputs.
The relays can be activated either above or below setpoint value. The graphs below show the different
relays stages in either below or above configuration. The NC contact will always be closed in case of power
failure. For setpoint configuration refer to Edit Setpoint page 11.
In order to prevent the relays from trigging during power up cycle each relay has a built in delay function
before normal operation is resumed.
12
3

PDR900 Operation manual 9
Searching for
transd
ucer...
901P LOADLOCK
MP readout PR1
Front panel
1. 5 Digit LED display
2. Setpoint indicators
3. User interface LCD display
4. Keyboard
5. Pressure unit indicator
6. Alarm indicator
Front panel
When the PDR900 controller is powered on it automatically searches for a
connected transducer in RS232 and RS485 mode. When the controller
recognizes the connected transducer it will initialize the menu interface and
only activate menus relevant for the current transducer type. Consequently the
menu structure varies, depending on the connected transducer type.
If no transducer is connected only a limited number of menus are available.
Alarm indicator
The alarm indicator provides a red light when the low or high alarm limit is exceeded.
Setpoint indicator
The multicolor 3 stage setpoint indicators provide a clear visual indication on the
setpoint relays status. When the relay is energized (C-NO) the setpoint indicator
illuminates green and when the relay is de-energized (C-NC) the indicator will
illuminate red. If the setpoint is disabled the indicator will be off.
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The setpoint indicators are updated via the digital interface and the built in relays are updated
directly by the transducer relays. Consequently the update rates of the indicators are slower
than the real time relay state changing.
Pressure unit indicator
The pressure unit indicator provides a visual indication of the current display and transducer pressure unit
setup. The pressure unit can be changed in the setup menu. Refer to setup unit page 13.
LED Display
The 5 digit LED main pressure display provides a clear and bright readout of the measured pressure.
For multi sensor transducers the various sensor readings can be displayed on the main display. To
change displayed sensor go to “Setup” and “Display”. See also page 13.

PDR900 Operation manual 10
ÆÆÆÆÆÆÆÆÆø
5
4
3
2
1 0+1+2
Setpoint 1:Clear
Value: 1.23E
4
Firmware Version
2.00
Time On
00008
9 hours
Model: 901P
LOADLOCK
MP: 7.80E+2
PZ: 1.00E 1
CMB: 7.62E+2
Max.Pr. 7.80E+2
Min.Pr. 1.23E
4
Menu interface
The up and down arrow keys are used to scroll the arrow pointer “ ¨å “ through the current menu. The left
arrow or Set key is used to access the menu at the arrow pointer. The Esc key leaves the current menu and
return to the previous menu level.
When entering parameters like setpoint values the Set key stores the current value and returns to the
previous menu level. The Esc key returns to the previous menu level without storing the edited value.
View menu
Graph
The graph display provides an analog bar graph reading of the displayed
pressure. The graph scale fits the measuring range of the connected
transducer.
PressureDisplay > Multi Reading
For transducers with multiple sensor, the Multi Reading menu provides
reading of 2 different sensors at the same time. Use the up and down arrow
keys to scroll between sensor outputs.
MP = MicroPirani™
PZ = Piezo
CMB = Combined
CC = Cold Cathode
HC = Hot Cathode
PressureDisplay > Min/Max Display
The controller stores the lowest measured pressure and the highest
measured pressure. The values are stored in the non volatile controller
memory and consequently the values are retained when power is turned off.
The user can reset the value by use of the reset menu. To allow the transducer to power up, there is a 30
sec. delay before logging min and max values.
Transducer information
The transducer information menu provides transducer model number, time
on, serial number, part number, firm/hardware versions, manufacturer,
temperature and status.
Refer to transducer operation manual for available transducer information.
Setpoint status
The setpoint status menu provides an easy view of the setpoint relays status.
When the relay is energized (C-NO) the status is Set and when the relay is
de-energized (C-NC) the status is Clear. The display provides the configured
value of the relay.
Controller information
The controller information menu provides controller serial number,
firm/hardware versions and time on.
ÆÆÆÆÆÆÆÆÆø
5
4
3
2
1 0+1+2
åGraph
PressureDisplay
Transducer
Setpoint Status
Controller

PDR900 Operation manual 11
Time: 00:00:10
CMB:4.56E
3 Torr
Datalogger Timer
Value: 00:00:10
DataloggerStatus
Logging 088/200
åStart logging
Stop logging
ÆÆÆÆÆÆÆÆÆø
0.1 1 10 100
DataloggerSource
Piezo
Data logger tool
The PDR900 has a built in data logging tool for real time logging and storing of measurements. The data can
later be downloaded and analyzed. The non volatile internal memory retains the logged measurements when
the controller is turned off. The memory has a capacity of 450 measurements.
View
The view display shows the logged measurements. The display shows the
log time, sensor type and the pressure data. Arrow up and down keys step
one measurement and arrow left and right jumps 10 measurements.
Timer
The time interval between each log can be set from 1 second to 99 hours.
The log time format is as follows: Hours:Minutes:Seconds
Status
The status displays provides information on the memory capacity status.
Control
The control menu starts and stops the data logger. When the data logger is
started the previous logged measurements are erased.
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It is not possible to change the transducer pressure unit when the data logger has
been activated.
Upload
The logged data can be uploaded at the upload menu to remote PC via RS232 or RS485 user interface. For
selecting interface refer to user communication setup on page 13.
The data can be uploaded to PC with standard communication software like Hyper Terminal and imported in
to spread sheets like Windows®Excel for data analyzing and storage. Each data line is separated by
carriage return (ASCII: 0x0D) in following format:
TIME;MP TORR
00:00:00;1.23E-4
00:01:00:1.24E-4
00:02:00:1.25E-4
00:03:00:1.26E-4
00:04:0……
Source
The source menu selects which sensor to use as source for the data logger.
For multiple-sensor transducers use up/down arrows to select sensor.
Leak detector tool
The leak detector tool is a gas leak detector for detection of rough leaks by the use of trace gas like helium. It
can be used in the pressure range from 1 to 400 Torr. The tool can only be used with MicroPirani™ based
transducers. The detectable leak rate depends on pumping speed, pressure range and chamber volume. For
Piezo/ MicroPirani™ based transducers the true differential measurement between the gas dependant
MicroPirani™ and the non gas dependant Piezo is displayed. For only MicroPirani™ based transducer the
leak detector measures the measured pressure difference from the zero value.
The leak detector must work at a relative stable pressure.
Leak detector procedure:
1. Stabilize pressure in the range from 1 to 400 Torr.
2. Zero the leak detector.
3. Spray helium around the possible leak.
If the bar graph pressure increases a leak has been found. The bar graph scale represents the leak rate in
an arbitrary unit. When displaying the bar graph the detector can be zeroed by use of the [SET] key.

PDR900 Operation manual 12
Enter pressure
4.00E
3 TORR
Enter pressure
5.00E
3 TORR
Direction 1
BELOW
Enable 1
ON
Enter pressure
+
1.00E+3 Torr
Enter pressure
+
9.00E
3 Torr
Action High
Loop
Edit menu
Set point
The PDR900 has 3 integrated set point power relays. The relays are controlled by the transducers set point
relays and consequently only one relay is available when using single set point transducers like the 902 and
925C.
The correct procedure for setting up set point parameters is:
1. Enter set point value
2. Select set point direction
3. Enter set point hysteresis value, if other than +/- 10% of set point value is required.
4. Enable and assign set point
Set point Value
The set point value is the pressure either below or above which the set point
relay will be energized.
Hysteresis Value
The hysteresis value is the pressure value at which the set point relay will be
de-energized.
Direction
The set point direction configures if the relay is energized above or below the
set point value.
Enable set point
The enable set point enables or disables the set point. For multi sensor
transducers like the 901P the set point enable also configures the set point to a
specific sensor either the differential piezo or absolute MicroPirani sensor.
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The Series 900 transducers have an auto hysteresis setting of 10% of the set point
value, that overwrites the current hysteresis value whenever the set point value or set
point direction is changed. If other hysteresis value than 10% is required, always set
the set point value and set point direction before setting hysteresis value.
Alarm
The audio alarm can be used for surveillance and warning of vacuum failures.
If the pressure exceeds a specific user defined high or low limit the audio alarm
will provide a warning. The audio alarm can either be set as a repeatable
warning or a momentarily audio signal. When the alarm is triggered the alarm
indicator on the front panel will be illuminated as long as the alarm limit is
exceeded.
The alarm value and setup is independent of transducer and stored in the controller non volatile memory.
Alarm Action
The alarm can either be a single beep or beep continuously. The high and low
alarm action can be configured individually.
Alarm Test
The test buzzer function illuminates the front panel alarm indicator and provides 5 beeps.
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When the unit is changed, the High/Low alarm values will change accordingly. The
High/Low alarm values are not affected if the unit is changed by the factory default
command. They have to be changed manually.

PDR900 Operation manual 13
Press SET when
pressure<5.00E
6
åLock Setup
Lock Controller
Display Sensor
Combined
Pressure Sensor
1
Curve Emulation
0
Cathode Power
ON
Analog output
Some transducers have one or two editable analog outputs. The Pressure
Sensor menu selects which sensor to use for the analog output. 1-5
corresponds to the PR1-PR5 output. Refer to transducer operation manual for
available transducer pressure readout.
The Curve Emulation menu, select which equation the analog output will use to
calculate the output voltage corresponding to the pressure. 0 is the MKS
standard curve emulation, Pressure (Torr) = 10(V-6).
Cathode Power
Turn on/off power for the Cold- or Hot Cathode.
Setup menu
Display setup
The 5 digit LED display can be set to additional pressure outputs provided by
the transducer. Refer to transducer operation manual for available transducer
pressure readout. For single sensor transducers like the 902 and 925C this
menu is not relevant.
Unit setup
The PDR900 can provide readout in the pressure unit mbar, Torr and the SI unit Pascal. The pressure unit
setup is stored in the transducer and consequently, the change of the unit will also change the unit of the
controller to the unit of the transducer.
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The unit can’t be changed when the data logger is active. Stop the current log session
to change the unit.
Calibration
The calibration menu enables adjustment of transducer measurement setup and calibration.
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Before executing any calibration commands always read the calibration procedure
described in the transducer operation manual. Failure to comply with the transducer
calibration procedure can result in large measurement errors.
All transducer calibration data is stored in the transducer memory and
consequently changes to these values will overwrite any existing transducer
calibration values.
If the transducer is calibrated at abnormal pressure or the transducer has a malfunction the display will
provide an error message.
Code protection
The PDR900 has a lock function to prevent any unauthorized access to the
setup of the controller and transducer parameters or to the entire menu
interface. To activate the lock enable lock setup or lock controller, and enter
the code. After confirming the code the lock is activated.
If the lock function has been activated and the code has been lost please contact MKS/HPS customer
service.
User tag
The transducer user tag sets the user tag label for the transducer.

PDR900 Operation manual 14
åTransducer Adr.
Transducer Baud
Controller Adr.
Controller Baud
Interface
Test interface
Sending text:
PDR900 adr 253
Controller Comm.
RS232 interface
Controller Comm.
Address: 253
Factory default
The factory default sets all parameter values for the controller or the transducer to the factory default
settings. Refer to transducer operation manual for transducer factory default values:
The factory default values for the controller are:
View Min.pressure 9.99E+09 Display setup PR1
View Max.pressure -9.99E+09 Unit setup Torr
Datalogger timer: 00:01:00 Controller user com adr. 253
Datalogger control Disabled Controller user com baud 9600
Datalogger source PR1 Controller user com interface RS232
Alarm high limit 1.00E+1 Lock Setup Disabled
Alarm low limit 1.00E0 Lock Controller Disabled
Alarm high action OFF
Alarm low action OFF
User communication
The PDR900 is equipped with both RS232 and RS485 user interface. The user communication interface
allows control of controller and transducer parameters as well as upload of data for storage and analyzing at
a remote PC.
Setup of user interface
The user interface is configured at the Setup>Communication menu. The data
format is 8 data bits, no parity and one stop bit.
The controller communication setup can either be configured by use of the
controller menu interface or by use of the setup commands.
For user interface cable specification, please refer to Electrical connections on
page 6. To configure the user communication interface first select interface type,
baud rate and finally the address.
Controller Address
The controller address menu returns or sets the address of the controller user communication interfaces.
Interface
The PDR900 controller is equipped with both RS232 and RS485 interface. The
user communication type can be viewed or configured at the interface menu.
Controller Baud rate
The communication speed is controlled by the baud rate. The higher baud value the faster communication.
The PDR900 user communication supports 2400, 4800, 9600, 19200, 115K baud rates (factory default
9600).
Test interface
The test interface function will send a text string to the host computer and can be
used for trouble shooting when setting up the computer communication.
Transducer Communication
The PDR900 can be used for configuration of transducer address and communication baud rate.
The address and baud rate values are stored in the transducer memory and consequently changing this
setting will change the setup of the transducer.
Transducer Address
The 900 Series transducers have an addressable user command set. The
transducer address menu returns or sets the address of the connected
transducer.
Transducer Baud rate
The transducer baud rate menu returns or sets the communication baud rate for the connected transducer.
The baud rate sets the communication speed, the lower value the slower communication speed. If a low
baud rate value is used the update rate of the display rating is also lower.

PDR900 Operation manual 15
Command Set
The PDR900 command set allows the user to change controller parameters. Settings and parameters, like
set point values, set point configurations and calibration data, are stored in the transducers. These settings
can be changed via the PDR900 user interface. For changing transducer settings and parameters refer to
the command set and procedures described in the transducer operation manual. Transducer operation
manuals are also available for download at www.mksinst.com.
Query and Command Syntax
Queries return current parameter settings; commands change the parameter setting according to the value
the user enters into the command syntax. Each query or command must begin with the attention character
@ and end with the termination ;FF.
The command syntax has an address parameter that enables connection of multiple devices in a RS485
network. The address parameter is also included in non network RS232 applications.
Address - ADC
The ADC command returns or sets the communication address for the controller. If multiple devices are
installed in a RS485 network, they can be addressed individually.
Values: 001 to 253 (default: 253)
Query Query Response Command Command Response
@254ADC?;FF @001ACK001;FF @001ADC!002;FF @002ACK002;FF
Baud Rate - BRC
Values: 2400, 4800, 9600, 19200, 115K
Query Query Response Command Command Response
@001BRC?;FF @001ACK9600;FF @001BRC!19200;FF @001ACK19200;FF
Factory Default - FDC
Command Command Response
@001FDC!;FF @001ACKFDC;FF
Firmware Version - FVC
Query Query Response
@001FVC?;FF @001ACK1.00;FF
Hardware Version - HVC
Query Query Response
@001HVC?;FF @001ACK1.00;FF
Serial Number - SNC
Query Query Response
@001SNC?;FF @001ACK000012345;FF
Time On - TIC
Query Query Response
@001TIC?;FF @001ACK000000024;FF
Download - DL
Query Query Response
@001DL?;FF @001ACKTIME;MB TORR<cr>
00:00:00;1.23E-4<cr>
00:01:00;1.21E-4<cr>
00:02:00;1.18E-4<cr>
00:03:00;1.12E-4<cr>
00:04:00;1.03E-4<cr>
00:05:00;9.65E-5<cr>
…
;FF
Datalogger Timer - DLT
Values: 00:00:00 - 99:59:59 (tt:mm:ss)
Query Query Response Command Command Response
@001DLT?;FF @001ACK00:05:00;FF @001DLT!01:00:00;FF @001ACK01:00:00;FF

PDR900 Operation manual 16
Datalogger Source- DLS
Values: PR1, PR2, PR3
Query Query Response Command Command Response
@001DLS?;FF @001ACKPR1;FF @001DLS!PR2;FF @001ACKPR2;FF
Datalogger Control - DLC
Values: START, STOP
Query Query Response Command Command Response
@001DLC?;FF @001ACKSTOP;FF @001DLC!START;FF @001ACKSTART;FF
Alarm High Limit - ALH
Values: Two- or three-digit scientific notation
Query Query Response Command Command Response
@001ALH?;FF @001ACK1.00E-2;FF @001ALH!1.00E-3;FF @001ACK1.00E-3;FF
Alarm Low Limit - ALL
Values: Two- or three-digit scientific notation
Query Query Response Command Command Response
@001ALL?;FF @001ACK1.00E-2;FF @001ALL!1.00E-3;FF @001ACK1.00E-3;FF
Action High - ACH
Values: OFF, SHORT, LOOP
Query Query Response Command Command Response
@001ACH?;FF @001ACKSHORT;FF @001ACH!LOOP;FF @001ACKLOOP;FF
Action Low - ACL
Values: OFF, SHORT, LOOP
Query Query Response Command Command Response
@001ACL?;FF @001ACKSHORT;FF @001ACL!LOOP;FF @001ACKLOOP;FF

PDR900 Operation manual 17
Searching for
transducer...
Zero adjustment
transd. error
Maintenance
In general, the PDR900 controller requires no maintenance other than proper installation and operation.
Refer to transducer operation manual for transducer maintenance.
Trouble shooting
Symptom Possible cause / Remedy
Transducer not found on power up. Check that transducer and transducer cable is compatible. Check
cable label and transducer part number. Ensure cable screw locks
are fastened.
Error message when executing
calibration.
Verify that the correct calibration procedure in the transducer
operation manual is followed.
Possible transducer defect.
No light in display or indicators. Check power switch is on. Check fuse at rear panel. Refer to fuse
change on page 16. Check AC supply voltage 100-240VAC.
Possible transducer defect. Disconnect transducer and turn
instrument on again. Possible controller defect.
Missing user communication. Check PC cable connection. Check computer baud rate and data
format match controller setup. Send test string from the
communication menu (see page 14).
Changing fuse
The PDR900 contains a main fuse protection. The fuse will blow if the instrument is
supplied with higher voltage than specified or in case of instrument malfunction.
1. Turn the instrument off and remove all connectors and finally
remove the power line.
2. Open the fuse holder located at the power inlet.
3. A spare fuse is mounted in the fuse holder. Change the fuse only
with approved fuses with 500mA, T rating.
4. Connect the external connections starting with the power line.
If the fuse blows again shortly after being changed, the instrument or the transducer has most likely a
malfunction and should be returned to MKS Service Center for repair.
Disposal (European Union only)
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The PDR900 is manufactured according to the RoHS directive.
For the benefit of the environment, at the end of life of the PDR900, it should not
be disposed in the normal unsorted waste stream. It should be deposited at an
appropriate collection point or facility to enable recovery or recycling.