Brooks Instrument VersaTorr BVT125 User manual

Installation & Operation Manual
VersaTorr BVT125
Ultra-wide Range Vacuum Gauge

Table of Contents
General information .......................................................................................................1
Symbols used................................................................................................................1
Intended use .................................................................................................................. 1
Safety information.......................................................................................................... 1
Disposal in the European Union .................................................................................... 1
Warranty........................................................................................................................1
Returns..........................................................................................................................1
Liability ..........................................................................................................................1
BVT125 vacuum gauge.................................................................................................2
About the BVT125 vacuum gauge .................................................................................3
BVT125 MEMS Pirani ATM vacuum gauge applications ................................................ 4
Part numbers.................................................................................................................6
Configuration accessories .......................................................................................................... 7
USB-powered converter and programmer ............................................................................... 7
Wall plug-powered USB converter and programmer .............................................................. 7
Software for configuration and on-screen measurement ........................................................ 8
Calibration .....................................................................................................................8
Mechanical installation...................................................................................................8
Application and process compliance..............................................................................8
Electrical installation .......................................................................................................8
Electrical connection (D-sub) .........................................................................................9
Electrical connection (Hirschmann GO-6 connector)...................................................... 9
Electrical connection (RJ45/8P8C connector) ................................................................ 10
Status LED ....................................................................................................................11
Signal-to-pressure conversion (0-10 VDC voltage output) .................................................... 12
Other vendors analog output emulation................................................................................... 12
Digital vacuum pressure and temperature measurement ..................................................... 12
Brooks Vacuum Gauge Communicator communication ..................................................13
Getting started ............................................................................................................................. 13
Brooks Vacuum Gauge Communicator LED signals .............................................................. 14
USB-to-Serial Converter .................................................................................................14
Command set ................................................................................................................14
Device Address (ADR) ...................................................................................................16
Analog Output Configuration (AOUT) ....................................................................................... 16
Set Baud Rate (BAUD) ..................................................................................................17
Button Enabled (BTN)....................................................................................................17
Sensor failure handling (FAIL)................................................................................................... 18
LED Behavior (LED) ...................................................................................................... 18
Pressure measurement (P) ............................................................................................19

Table of Contents
Quick data acquisitions (Q) ........................................................................................... 19
Temperature measurement (T)...................................................................................... 20
Unit (U) ......................................................................................................................... 21
Statistics (STAT) ........................................................................................................... 22
Switch function (Optional).............................................................................................. 23
Configuration of setpoint ............................................................................................................ 24
Pre-configuration of setpoint values......................................................................................... 25
Product information and identification ...................................................................................... 25
Serial number................................................................................................................ 25
Part number .................................................................................................................. 25
Manufacturer identity..................................................................................................... 25
Firmware version......................................................................................................................... 25
Maintenance ................................................................................................................. 25
Zero adjustment switch.................................................................................................. 26
Adjustment of the vacuum zero point............................................................................. 26
Adjustment of the ambient pressure zero point .............................................................. 27
Adjustment of full-scale................................................................................................. 28
Resetting to factory default ........................................................................................................ 29
900 Series vacuum gauge compatibility ........................................................................ 30
Specifications............................................................................................................................... 31
Accessories................................................................................................................... 33
Declaration of Conformity .............................................................................................. 34

Instruction Manual VersaTorr BVT125
1
Symbols used
The following symbols are used in this manual:
WARNING! Critical information to prevent dangerous situations that can result in serious injury or death.
CAUTION! Important information to prevent dangerous situations that can damage the device or auxiliary
equipment.
ACTION! Requires action or attention.
INFORMATION: Important recommendations and information for efficient use and best practice.
Intended use
The BVT125 vacuum gauge is intended for non-corrosive vacuum gas pressure measurement and control within the
limits listed in the specifications on page 34. The device is designed for KF fittings or screw-in fittings mounting.
The device complies with EMC (Electro Magnetic Compatibility) class B immunity requirements for industrial
environments.
Safety information
This product should be installed and operated by technically skilled or trained personnel only.
WARNING! This product is not intended for installation and use in the presence of flammable gases or other
explosive environments.
WARNING! Ensure that the gases or liquids exposed to the wetted materials are compatible with the wetted
materials described in the specifications table and the used sealing materials.
WARNING! The pressure rating of the sensor elements, connecting process fittings and sealing must comply
with the maximum possible pressure in the application.
The CE marking on the device does not apply to the pressure equipment directive (PED)
(2014/68/EU).
WARNING! Ensure that the process connection is tightened according to the recommended torque
specification. Ensure that there are no leaks from the process connection before pressurizing the
installation.
WARNING! Do not remove the gauge from the installation when the installation is evacuated, pressurized
or contains hazardous fluids.
Disposal in the European Union
At the end-of-life of this product, it must be disposed of according to the European Directive
2012/19/EU (WEEE). This product should not be mixed with general household waste.
WARNING! Ensure proper decontamination of the product before disposal if it has been exposed
to humanly or environmentally hazardous materials during its use.
For proper treatment, recovery and recycling, please take this product to designated collection points. Please contact
your local authority for further details of your nearest designated collection point.
Liability
The customer is solely responsible for determining the suitability and compatibility of the product for the customer’s
application, environment and intended use. Brooks Instrument is not liable for any claims arising from improper use,
incorrect installation or use with gases or liquid not compatible with the media wetted materials described in the
specifications table. To the extent permitted by law, Brooks Instrument is not liable for incidental and consequential
damages, including but not limited to loss of profits or revenue, overheads, loss of data, reinstallation costs, damage to
other equipment or any incidental or consequential damages of any nature.
Brooks Instrument has taken reasonable care to ensure that the content of its published information and
specifications is accurate and up-to date. However, Brooks Instrument does not guarantee or warrant that the content of
the published information is error-free. Brooks Instrument reserves the right to change its product specifications without
prior notice.

Instruction Manual VersaTorr BVT125
2
Electrical connection
LED indicator
Zero adjustment switch
Vacuum fittings
BVT125 vacuum gauge
The BVT125 is available with different electrical connections and vacuum fittings. The illustration below is an
example of the BVT125 with D-sub connector and DN16KF vacuum fitting.
Labeling
If the serial label should become unreadable, the serial- and part numbers are also stored in the internal non-
volatile memory and can be read using the Brooks Vacuum Transducer Communicator™ USB programmer
and communicator. See page 26.
Part number
Disposal symbol
Serial number
Pressure signal
Supply voltage range

Instruction Manual VersaTorr BVT125
3
About the BVT125 vacuum gauge
The BVT125 MEMS Piran ATM gauge is based on patent pending technology that offers best-in-class
performance and has established new standards by extending the useable measuring range for thermal
conductivity vacuum gauges by 1-3 decades. The MEMS Pirani ATM combines a MEMS
(Microelectromechanical Systems) heat-loss Pirani sensor and a Piezo diaphragm sensor with a barometric
pressure diaphragm sensor.
Piezo absolute diaphragm Heat-loss diaphragm pressure Barometric diaphragm sensor
The piezo MEMS sensor consists of a diaphragm where one side of the diaphragm is exposed to the vacuum
gas and the other side is exposed to a sealed reference vacuum. The applied pressure deflects the
diaphragm, and the deflection is converted to an electric signal.
The MEMS Pirani sensor is based on a resistive element deposited on an ultra-thin diaphragm suspended in
the vacuum gas to measure. The diaphragm is permanently mechanically fixed and does not bend or move
with changes in vacuum gas pressure. The resistive element is made of nickel that offers a high temperature
coefficient. The vacuum gas pressure is determined by measurement of the pressure dependent heat-loss
from a heated resistive element. The measurement of heat-loss is gas concentration and gas type dependent.
The barometric piezo MEMS sensor is based on the same measuring principle as the vacuum exposed piezo
diaphragm sensor. The barometric diaphragm sensor is exposed to the ambient pressure,
Measurement performance
The BVT125 MEMS Pirani ATM has established new performance standards and extended range for heat-
loss Pirani gauges. It combines a MEMS diaphragm piezo sensor and heat-loss MEMS Pirani sensor with a
barometric piezo diaphragm sensor.
The diaphragm sensor eliminates the well-known gas dependency in the rough vacuum range of thermal
conductivity gauges. The Piezo offers precision performance comparable to more expensive capacitance
manometers. This feature ensures more accurate control of vacuum system venting processes and
can prevent over-pressurization of the vacuum system.
The atmospheric referenced output is generated by subtracting the absolute diaphragm measurement in
vacuum with the barometric diaphragm sensor measurement in ambient pressure. This method provides a
measurement value relative to ambient pressure that allows accurate control of ventilation of vacuum
chamber to ambient pressure.
The MEMS-Pirani provides measurement resolution down to 1.00E-6 mbar (7.5E-7 Torr).

Instruction Manual VersaTorr BVT125
4
BVT125 MEMS Pirani ATM vacuum gauge applications
The BVT125 MEMS Pirani ATM gauge combines full-range vacuum measurement from high vacuum to
atmospheric pressure with accurate measurement of pressure relative to atmospheric barometric pressure.
A Load-lock is a vacuum chamber used in the vacuum and semiconductor industry for loading devices like
semiconductor wafers from ambient air pressure conditions into the main vacuum processing chamber. In
the semiconductor in
du s tr y , the process vacuum chamber is maintained at high vacuum pressure and not
vented to ambient pressure during process cycles. An auxiliary vacuum chamber is required to isolate the
wafers from the main process chamber when ventilated.
The load-lock is typically cycled between atmospheric barometric ambient pressure and an adequate vacuum
pressure required to transfer the wafers device to the processing vacuum chamber via a buffer transfer
chamber. Accurate control of the vacuum gas pressure in the load-lock vacuum chamber is critically important
in order to prevent inrush of ambient air and particulate contamination of the load-lock and wafers.
Contamination by inrush of ambient air will cause longer pump-down times and increases the risk of
particulate contamination of both wafers and the vacuum system itself.
Load-lock pumping cycle
To control pressure during the pumping cycle, a Pirani heat-loss gauge is typically used to measure the vacuum
gas pressure and to provide a set-point control signal once the vacuum pressure between the load-lock and
transfer chamber is equalized. The wafer is mechanically transferred to the transfer chamber and a processed
wafer is transferred back to the load-lock. The load-lock is typically ventilated with Nitrogen gas to ambient
pressure or a small overpressure to prevent atmospheric air to flow into the load-lock chamber when opened.
Load-lock venting to atmosphere cycle
To control the pressure in the venting cycle a vacuum sensor measuring relative to ambient pressure,
commonly known as a gauge sensor, is used. The advantage of using a gauge sensor instead of an
absolute sensor is that the load-lock pressure can be accurately equalized to zero differential pressure
between the load-lock vacuum chamber and ambient pressure independently of variation in barometric
ambient pressure due to weather changes.
Load-lock external control
The BVT125 MEMS Pirani ATM is available with three independent setpoint solid-state relays that can be used
to control external devices like valves, door, pumps or safety interlock circuits.
Each setpoint can programmed to a setpoint and hysteresis value that can be assigned to the pressure reading
relative to ambient pressure or the wide-range absolute range.

Instruction Manual VersaTorr BVT125
5
Load-lock applications
Fast cycle time of the load-lock is important to optimize the wafer processing cost. Use of accurate and
modern load-lock control can shorten cycle times. Load-lock vacuum systems are not only used in the
semiconductor in du s t ry , but also in analytical equipment, like scanning electron m ic r o s co p e s , where samples
are transferred from ambient pressure to the analysis vacuum chamber.
In a PVD (Physical Vapor Deposition)
s y s tem , it can also be an advantage to maintain the processing
deposition chamber under permanent vacuum pressure and only having to vent an axillary load-lock vacuum
chamber.
Single-chamber PVD systems have a large door system to the ambient pressure to load the carousels with the
coating objects. The large door surface requires accurate control of the venting process to both prevent over
pressurization of the vacuum chamber and to equalize the pressure in order to open the door.
Many vacuum processes and types of vacuum systems, where samples,
w a f er s , test o b jec t s , substrates or
other devices need to be transferred from ambient air to the vacuum
s y s te m , can benefit from having an
auxiliary load-lock system to ensure fast cycle-
t im e s , system uptime, reduced particulate contamination and
water vapor contamination. Such applications include mass
s p e c tro m e t e rs , scanning electronics
microscopes and freeze-drying equipment.

Instruction Manual VersaTorr BVT125
6
Part numbers
The BVT125 is available with different electrical connections and process fittings. The illustration below is an
example of the BVT125 with
D N1 6 K F , RS-232/Brooks Vacuum Transducer C om muni c a t o r ™ , 0.5-9.6 VDC
analog output, mbar unit, 3 relays and 15-pin HD D-sub connector.

Instruction Manual VersaTorr BVT125
7
Part number Description
Part number Description
Configuration accessories
When configuring the various digital and analog parameters of the BV T 125 , three different categories of
connectors can be used
– as described in the following sections.
Neither of these connectors are included with the gauge and must be purchased separately.
USB-powered converter and programmer
The USB-powered converter and programmer provides direct USB
communication and power from the PC.
The USB-powered programmer is compatible with BVT125
transducers and MKS
901 P , 902 B , 910 and 925 transducers.
Part number
Description
BVT-RS2-DS15-UP
RS-232 USB programmer, 1.5 m cable, D-sub 15 pin, USB powered
BVT-RS2-DS9-UP
RS-232 USB programmer, 1.5 m cable, D-sub 9 pin, USB powered
Wall plug-powered USB converter and programmer
The wall plug-powered variant includes either a USB-to-RS-232 or USB-
to-RS-485 converter along with a 90-230 VAC wall plug power supply
that enables powering of the gauge independently of a PC.
The wall plug power supply is compatible with BVT125 transducers
and MKS
901P , 902B , 910, 925, 971B , 972B and 974B.
BVT-RS2-DS15-WP RS-232 USB programmer, 1.5 m cable, D-sub 15 pin, wall plug-powered
BVT-RS2-DS9-WP
RS-232 USB programmer, 1.5 m cable, D-sub 9 pin, wall plug-powered
Brooks Vacuum Transducer Communicator
The Brooks Vacuum Transducer Communicator
communicates digitally via the power supply line, enabling
configuration of products that would otherwise not have a
standard digital interface like RS-232 or RS-485.
Brooks Vacuum Transducer Communicator is available in four configurations:
BVT-S4-DS15 Brooks Vacuum Transducer Communicator™ USB programmer, 1.5 m cable, D-
s ub , 15-pin
BVT-S4-RJ45 Brooks Vacuum Transducer Communicator™
USB programmer, 1.5 m cable,
RJ45, 8-pin
BVT-S4-HIR6
Brooks Vacuum Transducer Communicator™ USB programmer, 1.5 m cable,
Hirschmann GO-6, 6-pin
BVT-S4-DS9
Brooks Vacuum Transducer Communicator USB programmer, 1.5 m cable, D-
sub, 9-pin
BVT-RS4-DS9-WP RS-485 USB programmer, 1.5 m cable, D-sub 9 pin, wall plug-powered
BVT-RS4-DS15-WP RS-485 USB programmer, 1.5 m cable, D-sub 15 pin, wall plug-powered

Instruction Manual VersaTorr BVT125
8
Software for configuration and on-screen measurement
The Brooks Vacuum Transducer Communicator™ and RS-232/485 software is freeware and can
be downloaded from the Brooks Instrument website: https://BrooksInstrument.com/support/
Calibration
The BVT125 is delivered factory-calibrated with a calibration test report. An optional accredited calibration
traceable to national standards can also be supplied with the BVT125 gauge.
Mechanical installation
The BVT125 gauge is available with KF clamp fittings or screw-in fittings.
CAUTION! For screw-in fittings do not exceed tightening torque values.
CAUTION! Use gloves when handling vacuum fittings. Ensure that the O-ring and vacuum sealing
surfaces are clean and free of scratches or other damages.
The BVT125 gauge can be mounted horizontally or vertically without impact on accuracy or performance.
Application and process compliance
The BVT125 gauge is intended for use in vacuum applications where non-corrosive gases are present.
Electrical installation
The BVT125 requires an external power supply supplying in the range 12-30 VDC. The external power supply
shall be with safe isolation according to PELV (Protective Extra Low Voltage) requirements of EN60204-1.
The gauge is protected against momentary overvoltage on the supply line. The internal 100 mA thermal fuse
will limit current draw in case of overvoltage to limit overheating.
A dd iti o n al ly , the gauge is protected against reverse polarity caused by incorrect wiring to the power
supply.
The gauge electronics have a high level of immunity against external electromagnetic interference.

Instruction Manual VersaTorr BVT125
9
Electrical connection (D-sub)
The voltage output version provides a voltage signal proportional to the measured pressure.
The high resolution 16-bit voltage signal can be interfaced to a P L C , A/D converter, voltmeter or other readout
devices.
INFORMATION: It is recommended to use a differential input to measure the output signal that uses
a separate signal return wire connected to the gauge connector. If power supply return and
signal return share the same wire connection the voltage drop as function of supply current will
cause a measurement deviation. In that c as e , the measurement deviation will increase with the cable
length.
Connector pinout and cable wiring (0-10 VDC voltage output)
15-pin HD D-sub connector
(1) Optional relay
Pin
Symbol
Description
1
RS232TX
RS-232 Transmit / RS-485 (-)
2
RS232RX
RS-232 Receive / RS-485 (+)
3
V+
Supply voltage 12-30 VDC
4
GND
Supply voltage – (return)
5
S+
Analog voltage signal +
6
GND
Analog voltage signal – (return)
7
REL NO
Relay 1 NO (normally open contact) (1)
8
REL COM
Relay 1 Common (1)
9
REL NC
Relay 1 NC (normally closed contact)
(1)
10
REL NC
Relay 2 NC (normally closed contact)
(1)
11
REL COM
Relay 2 Common (1)
12
REL NO
Relay 2 NO (normally open contact)
(1)
13
REL NC
Relay 3 NC (normally open contact)
(1)
14
REL COM
Relay 3 Common (1)
15
REL NO
Relay 3 NO (normally open contact)
(1)

Instruction Manual VersaTorr BVT125
10
9-pin D-sub connector
Pin
Symbol
Description
1
REL NO
Relay 1 NO (normally open contact)(1)
2
REL NC
Relay 1 NC (normally closed contact)
(1)
3
V+
Supply voltage 12-30 VDC
4
GND
Supply voltage – (return)
5
S+
Analog voltage signal +
6
REL COM
Relay 1 Common(1)
7
RS- 232TX
RS-232 Transmit / RS-485 (-)
8
GND
Analog voltage signal – (return)
9
RS- 232RX
RS-232 Receive / RS-485 (+)
(1) Optional relay
Electrical connection (RJ45/8P8C connector)

Instruction Manual VersaTorr BVT125
11
Pin
Symbol
Description
1
V+
Supply voltage 12-30 VDC
2
GND
Supply voltage – (return)
3
S+
Analog pressure voltage signal +
4
ID
Identification resistor(7)
5
GND
Analog voltage signal – (return)
6
REL2
Relay 2 Setpoint (closing contact)
7
REL1
Relay 1 Setpoint (closing contact)
8
RELC
Relay 1 and 2 common
RJ45/8P8C connector
(7) Identification resistor for RJ45/8P8C connector
The identification resistor is used by external equipment to identify the type of gauge. External equipment can
be a display or a controller from another vendor. The BVT125 is available with different ID resistors. The ID
resistor is identified by the last digit in the part number:
P/N
ID resistor value
5
27 K Ω
6
36 K Ω
7
43 K Ω
INFORMATION: It is recommended to use a differential input to measure the output signal that uses
a separate signal return wire connected to the gauge connector. If power supply return and
signal return share the same wire connection the voltage drop as function of supply current will
cause a measurement deviation. In that c as e , the measurement deviation will increase with the cable
length.
Status LED
The LED indicator signals the gauge status and can indicate following basic indications:
Startup sequence
0.5 sec purple followed by 4 sec. pulsing green
Normal standard operation
Solid green
Overpressure indication (in Dynamic Mode only)
Flashing green / yellow (5 Hz)
Brooks Vacuum Transducer Communicator mode
Pulsing green
Sensor fail stage
Flashing red (5 Hz)
RGB LED for pressure indication
The MEMS Pirani™ ATM introduces a new approach for visually determining the measured pressure
by a multi-color LED that smoothly changes color throughout the pressure range. This selectable
visual function is a low-cost alternative to integrated displays and provides a rough visual indication
of the measured pressure. It also provides a clear visual warning if the vacuum system is pressurized
above ambient pressure.

03
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2
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VersaTorr BVT125 Installation & Operation Manual
12
Signal-to-pressure conversion (0-10 VDC voltage output)
The gauge can provide a voltage output from 0-10 VDC and is available with different types of pre-
configured output scaling.
In the BVT125’s standard configuration with a voltage output of 1 VDC/decade, the output is scaled according
to the configured pressure unit, e.g. when mbar is selected the gauge will provide 1 VDC per decade mbar.
L i k ewi s e , when the unit is changed to torr, the gauge will provide 1 VDC per decade torr. Finally, when the unit
is changed to
Pas c al , the gauge will provide 1 VDC per decade Pascal.
The voltage signal  can be converted to pressure using the following linear expression:
Voltage to pressure conversion (mbar and torr): 
(

)
= 10(−6.5)
Voltage to pressure conversion (Pascal):
() = 10
(−4.5)
Other vendors analog output emulation
The BVT125 analog output emulation offers voltage output pressure scaling compatible with other vendors
gauges. This feature enables drop-in replacement of gauges from other vendors.
Configuration and list of analog output options can be found on page 17-18.
Digital vacuum pressure and temperature measurement
The real-time digital vacuum gas pressure value and vacuum gas temperature can be acquired through the
digital interface. Refer to digital command set on page 17.

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VersaTorr BVT125 Installation & Operation Manual
13
Brooks Vacuum Transducer Communicator™ communication
The Brooks Vacuum Transducer Communicator™ USB programmer and communicator provides access from
PC software via a USB interface to the digital core of the gauge. It is compatible with both 4-20 mA current
output and 0-10 VDC voltage output transducers from Brooks Instrument.
It is intended for configuration, calibration and setup of the unit, but it can also be used to acquire
measurement data and perform diagnostics using a PC.
The Brooks Vacuum Transducer Communicator™ interface enables easy and cost-optimized access to
perform calibration, adjustments and individual configuration of the gauge product to fit the customer
application and requirements.
During the power-up cycle the gauge will detect if there is a Brooks Vacuum Transducer Communicator™
programmer connected and if so, the gauge will enter the Brooks Vacuum Transducer Communicator™
service mode.
WARNING! The Brooks Vacuum Transducer Communicator™ interface is not intended for digital
communication between process equipment and the BVT125 gauge unit. Disconnect the gauge
from any external installation before enabling the Brooks Vacuum Transducer Communicator™
service mode. During the Brooks Vacuum Transducer Communicator™ service
mode the analog
voltage output or analog current output will be disabled, and the analog output will
be used for
digital communication between gauge and Brooks Vacuum Transducer Communicator™
programmer.
Getting started:
1. Remove the electronics connection to the gauge so that it is disconnected from any process
equipment.
2. Download the Brooks Vacuum Transducer Communicator™ software from
www.BrooksInstrument.com and install the software.
A lte rn ati ve l y , a standard serial terminal
software can be used.
3. Connect the programmer to the PC and the Brooks Vacuum Transducer Communicator™ software.
The Brooks Vacuum Transducer Communicator™ programmer will then enter a state where it searches
for the gauge. During this period the LED on the programmer will alternate between green and
blue.
4. Connect the gauge to the Brooks Vacuum Transducer Communicator™ cable. The Brooks Vacuum
Transducer Communicator™
p r o g r a mm e r ’ s LED will turn solid green if a current output gauge is
connected and solid blue if a voltage output gauge is connected.
5. When the Brooks Vacuum Transducer Communicator™ p r o g r a mm e r ’ s LED turns solid blue or g r ee n ,
it’s ready for communication.

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VersaTorr BVT125 Installation & Operation Manual
14
Brooks Vacuum Transducer Communicator USB programmer LED signals
The Brooks Vacuum Transducer Communicator™ USB programmer has an LED indicator that provides the
following signals:
Alternating blue/green: Searching for gauge.
Solid blue:
Voltage output gauge connected.
Solid
green: Current output gauge connected.
White strobe: Locate mode for Brooks Vacuum Transducer Communicator™ programmer
(see page 19).
USB-to-Serial Converter
The USB-to-Serial Converter is the quickest and simplest way to provide connectivity between an RS-232 or
RS-485 capable Brooks Instrument gauge and a computer or other compatible device.
Featuring a built-in switch-mode power s upp l y , the converter eliminates the need for an external power supply.
Command set
The BVT125 is available with Brooks Vacuum Transducer Communicator and either an RS-232 or an RS-485
serial interface. Communication is based on an ASCII protocol that includes a start character, device
address, command or query and an end character for termination:
@<device address><command or query><? or !><parameter>\
Start character:
Device address:
Command:
Query or set:
Parameter:
End character: \
INFORMATION: Throughout this manual the signs <> are written for separation of command name and
values and are for informational purposes only. These signs should not be entered in the actual
command
Example of how to send a command to the gauge
Programming the Setpoint 1 value to 1.23E-4 (using the default unit setting of the gauge, i.e. mbar):
Send:
Reply:
@254SPV!1,1.24E-4\
@253ACK1.23E-4\
@
001
- 253
See
command list

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VersaTorr BVT125 Installation & Operation Manual
15
The following table lists all commands supported by BVT125. Each command is described in more detail
below the table.
Command
Description
Query
Set
Valid input parameter
ADR
Device address
●
●
1-3 digits (range 001-253)
AOUT
Analog output configuration
●
●
<STD / 0-39>
ATD
Atmospheric Piezo
adjustment
●
●
<(AMBIENT PRES.) / CLEAR>
ATZ
Differential Piezo zero
adjustment
●
●
<(NONE) / CLEAR>
BAUD
Set baud rate
●
●
<4800 / 9600 / 19200 / 38400 / 57600 /
115200> (default 9600)
BTN
Button enabled
●
●
<ON / OFF>
FAIL
Sensor failure handling
●
●
<WORKING / ZERO >
FD
Factory default
●
●
<ADR / ATD / ATZ / AO / BAUD / FS / GT
/ SP / U / VAC / (NONE)>
FS
Piezo full-scale adjustment
●
●
<PRESSURE VALUE / CLEAR>
FV
Firmware version
●
-
GT
Gas type
●
●
<NITROGEN / HELIUM / ARGON / AIR>
LED
LED Behavior
●
●
<SOLID / DYNAMIC>
MF
Manufacturer
●
-
MD
Model name
●
-
P
Pressure measurement
●
<CMB / MP / PZ / (none)>
PN
Part number
●
-
Q
Quick query
●
●
<Parameter 1>, <Par. 2> … <Par. 5>
SN
Serial number
●
-
SP
Setpoint settings
●
-
SPD
Setpoint direction(1)
●
●
<SETPOINT #> , <ABOVE / BELOW>
SPE
Setpoint enable(1)
●
●
<SETPOINT #> , <OFF / ON / PZD>
SPH
Setpoint hysteresis(1)
●
●
<SETPOINT #>, <PRESSURE VALUE>
SPV
Setpoint value
(1)
●
●
<SETPOINT #>, <PRESSURE VALUE>
SPR
Setpoint relay status
(1)
●
<SETPOINT #>
SPS
Setpoint source(1)
●
●
<SETPOINT #> , <P / T / CMB / VAC /
ATM / DIFF / PIR>
STAT
Statistics
●
●
<P / T / (none) / CLEAR (Set only)>
T
U
Vacuum sensor temperature
Pressure unit
●
●
●
-
( <P A R A M ET ER > ) , <MBAR / PASCAL /
TORR> or <CELSIUS / FAHRENHEIT /
KELVIN>
VAC Pirani Zero adjustment ●●No input or <PRESSURE VALUE>
General note: all valid input parameters written in italics are to be entered as a number. These numbers will vary with the type
and model number of the gauge. Refer to the specific commands for details.
(1) Setpoint solid-state relay is optional and is not relevant for all part numbers.

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Device Address (ADR)
The BVT125 has an addressable communication protocol, and so it will only accept commands or queries
with the following addresses. All queries or commands sent to all other addresses are simply ignored.
<device address> Pre-configured to 253, this value may be changed at any time to anything in
the range 1-253 using the ADR command.
254 This is the ”global” address. The BVT125 will always respond to commands
or queries at address 254, regardless of the device address setting.
255 This is the broadcast add r e ss , which may be used for performing the same
operation on multiple BVT125s at once. The BVT125 will not issue any replies
to broadcast commands. Note that broadcasting requires a multidrop
communication interface such as RS-485.
Example: Change the device address from 253 (default) to 123 using the global address:
Send: @254ADR!123\
Reply: @253ACK123\
All replies after this one will begin with the new device add re ss , 123.
Analog Output Configuration (AOUT)
BV T 125 ’ s default analog output is 0.5-9.5 V , 1V / de ca de , however, the analog output can be configured to
emulate a collection of other equipment via the AOUT command:
Vendor
Transducer model
Output
0
MKS
901P, 910, 925
1 VDC/decade
1
Edwards
APG-L
1.99 - 10 VDC
2
Edwards
APG-100
2.00 – 9.00 VDC
3
Edwards
WRG
2.75 – 10.00 VDC
4
Inficon
Leybold
PSG500
TTR91
1.547 – 10.00 VDC
5
Inficon
Pfeiffer
MPG400
PKR251
2.07 – 8.603 VDC
6
Inficon
MKS
BPG400
999 Quattro
1.843 – 10.00 VDC
7
MKS Granville Phillips
275
0.372 – 5.570 VDC
8
MKS HPS
Moducell 325
0.2509 – 3.2398 VDC
9
MKS HPS
Moducell 325 x3
0.753 – 9.719 VDC
10
MKS
Baratron® 0.1 Torr
0 - 10.00 VDC
11
MKS
Baratron® 1 Torr
0 - 10.00 VDC
12
MKS
Baratron® 10 Torr
0 - 10.00 VDC
13
MKS
Baratron® 100 Torr
0 - 10.00 VDC
14
MKS
Baratron® 1,000 Torr
0 - 10.00 VDC
15
MKS
901P piezo differential output
1 VDC/decade
16
Edwards
AIM-S / - SL
2.5 – 10.00 VDC
17
Edwards
AIM-X / XL
3.286 – 9.799 VDC
18
Pfeiffer
IKR251
2.324 – 8.500 VDC
19
Pfeiffer
TPR 265 / 280
2.199 – 8.625 VDC
20
Hastings
HPM-2002-OBE special
5.00 – 9.995 VDC
21
Edwards
DV6M
2.00 – 10.00 VDC
22
Edwards
APG- M
2.00 – 10.00 VDC
23
MKS Granville Phillips
GP275 (0-9.0 VDC)
0 – 9.00 VDC
24
Thyracont
MT 241.1
0.41 – 9.99 VDC

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25
MKS Granville Phillips
GP275 (0.375-5.659 VDC)
0.375 – 5.659 VDC
26
Edwards
APG100- LC
2.00 – 10.00 VDC
27
Edwards
APG100M
2.00 – 10.00 VDC
28
MKS
907
0.387 – 5.666 VDC
29
Alcatel
K6080
0.40 – 10.00 VDC
30
Inficon
PEG100
2.186 – 10.166 VDC
31
Varian
Eysys
1.00 – 8.00 VDC
32
Alcatel
TA111
0.10 – 9.20 VDC
33
MKS
685
1.00 – 7.00 VDC
Example: Change the Analog output emulation to MKS Baratron 0.1 Torr:
Send: @254AOUT!10\
Reply: @253ACK10\
Set Baud Rate (BAUD)
The BVT125 supports the following baud rates: 4800, 9600, 19.000, 38.400, 57.600, 115.200. Note that
whenever the baud rate is
c han g ed , the BVT125 will send an acknowledgement to the BAUD command using
the old baud rate setting before switching to the new one.
Example: Change the baud rate to 115.200:
Send: @254BAUD!115200\
Reply: @253ACK115200\
Button Enabled (BTN)
Enable or disable the feature to perform Pirani zero-adjustments and Differential Piezo zero-adjustments via
the
BV T 125 ’ s push-button.
Example: Disable the push-button.
Send: @254BTN!OFF\
Reply: @253ACKOFF\