Teledyne HVG-2020B User manual

HVG-2020B
INSTRUCTION MANUAL
I S O 9 0 0 1
C E R T I F I E D
www.teledyne
-
hi.com
Use and Disclosure of Data
Information contained herein is classified as EAR99 under the U.S. Export Administration Regulations.
Export, reexport or diversion contrary to U.S. law is prohibited.

HVG-2020B Instruction Manual
EAR99 Technology Subject to Restrictions Contained on the Cover Page Page 2 of 40
Manual Print History
The print history shown below lists the printing dates of all revisions created for this manual. The revision level
letter increases alphabetically as the manual undergoes subsequent updates. Each new revision includes a
revised copy of this print history page.
Revision A (Document Number 182-082019) .................................................................................................................................... August 2019
Revision B (Document Number 182-102019).................................................................................................................................... October 2019
Revision C (Document Number 182-052020) ........................................................................................................................................ May 2020
Revision D (Document Number 182-082020).................................................................................................................................. August 2020
Revision E (Document Number 182-012022) .................................................................................................................................... January 2022
Visit www.teledyne-hi.com for WEEE disposal guidance.
Description of Symbols and Messages used in this manual
WARNING: indicates a hazardous situation, which, if not avoided, could result in death or
serious injury. Do not proceed beyond a WARNING notice until the indicated conditions are
fully understood.
CAUTION: indicates a hazardous situation, which if not avoided, could result in minor or
moderate injury. Do not proceed beyond a CAUTION notice until the indicated conditions are
fully understood and met.
NOTICE: calls attention to a procedure or practice that if not correctly performed or adhered
to, could result in equipment damage, loss of data, or inaccurate data.
NOTE: is used for tips and other digressions.
Hastings Instruments reserves the right to change or modify the design of its equipment without any
obligation to provide notification of change or intent to change.

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Table of Contents
1. GENERAL INFORMATION ................................................................................................. 5
FEATURES .............................................................................................................. 6
SPECIFICATIONS ......................................................................................................... 7
ACCESSORIES ........................................................................................................... 8
1.3.1. Power Supplies................................................................................................ 8
1.3.2. Cables .......................................................................................................... 8
2. INSTALLATION AND SETUP .............................................................................................. 9
RECEIVING INSPECTION .................................................................................................. 9
MECHANICAL CONNECTIONS ............................................................................................. 9
2.2.1. Mounting ....................................................................................................... 9
2.2.2. Plumbing ..................................................................................................... 10
ELECTRICAL CONNECTIONS ............................................................................................ 10
2.3.1. Connector ................................................................................................... 10
2.3.2. Power Input ................................................................................................. 10
2.3.3. Analog Output .............................................................................................. 11
2.3.4. Setpoints .................................................................................................... 17
2.3.5. Serial Connection........................................................................................... 18
2.3.6. USB Connection ............................................................................................. 18
2.3.7. TTL Serial Connection ..................................................................................... 18
PUSH-BUTTON OPERATION ............................................................................................ 19
LED OPERATION ...................................................................................................... 19
QUICK START ......................................................................................................... 20
3. DISPLAY OPERATION ................................................................................................... 21
GENERAL ............................................................................................................. 21
VIEW ICON ........................................................................................................... 21
MENU BUTTON ....................................................................................................... 22
3.3.1. Screen Orientation ......................................................................................... 23
3.3.2. Set Zero ...................................................................................................... 23
3.3.3. Device Info .................................................................................................. 23
3.3.4. Analog Output .............................................................................................. 23
3.3.5. Gas Select ................................................................................................... 23
3.3.6. Serial Port ................................................................................................... 23
3.3.7. Restore Factory Defaults .................................................................................. 23
4. GENERAL OPERATION .................................................................................................. 24
OPERATING CONDITIONS .............................................................................................. 24
ZERO CHECK .......................................................................................................... 24
PIEZO SENSOR AUTO-ZERO............................................................................................ 24

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POSITIVE PRESSURE OPERATION ....................................................................................... 24
TEMPERATURE AND HUMIDITY EFFECTS ................................................................................ 24
PIRANI AND GAS INTERACTIONS ........................................................................................ 25
CALIBRATION PROCEDURE ............................................................................................. 25
5. DIGITAL OPERATION .................................................................................................... 27
INSTRUMENT STATES .................................................................................................. 27
SERIAL COMMUNICATIONS ............................................................................................. 27
5.2.1. General ...................................................................................................... 27
5.2.2. Serial Communication Software.......................................................................... 27
5.2.3. The Sensor Lists ............................................................................................ 27
5.2.4. Command Prompt .......................................................................................... 27
5.2.5. Command Format .......................................................................................... 28
5.2.6. RS232 / RS485 Mode ....................................................................................... 28
5.2.7. Response Format ........................................................................................... 28
5.2.7.1. Response Line Termination ......................................................................................... 28
5.2.7.2. RS485 Mode Responses .............................................................................................. 29
5.2.8. Commands ................................................................................................... 29
5.2.8.1. Reporting Commands ................................................................................................ 29
5.2.8.2. System Commands ................................................................................................... 29
5.2.8.3. State Commands ..................................................................................................... 32
5.2.8.4. Sensor List Commands .............................................................................................. 33
6. TROUBLESHOOTING .................................................................................................... 38
AUTHORIZED MAINTENANCE ........................................................................................... 38
TROUBLESHOOTING ................................................................................................... 38
6.2.1. Instrument Lists and Codes ............................................................................... 38
6.2.2. Possible Problems and Solutions ......................................................................... 38
7. WARRANTY ............................................................................................................... 39
WARRANTY POLICY ................................................................................................... 39
RETURN POLICY ...................................................................................................... 39
8. DRAWINGS ................................................................................................................ 40

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1. General Information
The HVG-2020B is a small, low-cost electronics module which combines the outputs of a Pirani sensor and a
piezo-resistive sensor to provide the user with accurate vacuum measurements over the range of 1×10-4 Torr to
1000 Torr. The piezo-resistive sensor produces an absolute pressure signal output that is proportional to
pressure and independent of gas composition. The hot-wire Pirani sensor produces an absolute pressure signal
dependent on the thermal conductivity of the surrounding gas remaining in the vacuum system.
The HVG-2020B is designed for quick, easy installation and will provide the user with long lasting, trouble free,
reliable vacuum measurement. The electronics can be powered by a power supply capable of delivering any
voltage between 12 VDC to 36 VDC.
The HVG-2020B instrument has a modular PCB design that allows for flexibility in available features and options
for OEM applications. This includes analog output via a 9-pin D connector, additional 4 conductor 3.5 mm TRRS
jack and USB virtual COM port for digital communication. The HVG-2020B VISION offers an additional color
touch-panel display.
The two sensors exhibit excellent stability, and their outputs are characterized and digitally linearized to
provide superior accuracy. The pressure signal is made available on the digital port and display. The signal is
also converted to the desired analog signal (linear/logarithmic, voltage/current) and this signal is presented to
the D connector.
Hastings vacuum instruments do not require any periodic maintenance under normal operating conditions with
clean gases. No damage will occur from the use of moderate overpressures (< 25 psig).
The following sections contain the steps needed to get a new vacuum gauge operating as quickly and easily as
possible. Please read the following thoroughly before attempting to install the instrument.
NOTICE: The instruments described in this manual may be available with multiple pinouts.
Ensure that all electrical connections are correct.
NOTICE: The instruments described in this manual are designed for INDOOR use only.
NOTICE: The instruments described in this manual are designed for Class 2 installations in
accordance with IPC standards.
CAUTION: There are no operator serviceable parts or adjustments inside the product.
CAUTION: If this equipment is used in a manner other than that specified, the protection
provided by the equipment may be impaired.

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Features
COLOR DISPLAY WITH TOUCH PANEL. The HVG-2020B has an optional integrated touch panel color LCD
display. This gives the user easy configurability, stand-alone operation and local control over the instrument.
SUPERIOR ACCURACY. The output of the transducer is thermally compensated and linearized to provide
accuracy of ± (0.1% of reading + 0.3 Torr) between 1000 Torr and 10 Torr, better than ± (5% of reading +
0.00025 Torr) between 10 Torr and 1 mTorr, and better than 10% of reading + 0.00025 mTorr less than 1 mTorr
after zero adjustment.
GAS CORRECTION. The piezo-resistive sensor is media isolated and provides a direct pressure measurement
that is gas species independent. There are internal corrections available for the Pirani sensor when used with
other gases.
NO ELASTOMERS. The vacuum envelope of the HVG-2020B is entirely 300 series stainless steel with welded
construction and glass-to-metal seals. Using metal seal vacuum connections eliminates the permeation,
degradation and outgassing problems of elastomer O-rings.
FLEXIBLE POWER REQUIREMENTS. The HVG-2020B can operate with any power supply capable of providing 12
– 36 VDC via the 9-pin D connector or a 2 mm bayonet jack connection.
DIGITAL COMMUNICATIONS. The HVG-2020B is equipped with RS232/RS485 and USB for digital
communications. The USB connector serves as a virtual COM port for serial communication, eliminating the
need for a USB to Serial converter.
ANALOG OUTPUTS. The pressure is available in analog form as either a voltage or current signal on either a
logarithmic or linear scale. The 0-20 mA or 4-20 mA current option gives the user the advantages of a current
loop output to minimize environmental noise pickup and signal loss over long cable runs.
TTL ALARMS. Two alarm signals are provided with an open-drain configuration, one to indicate when pressure
goes above a value and the other below a value.
LED INDICATORS. Two LEDs provide instrument status and system pressure information.

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Specifications
WARNING: Do not operate instruments exceeding the specifications listed below. Failure to
heed this warning could result in serious personal injury and/or damage to the equipment.
Range: 1x10-4 Torr to 1000 Torr
Accuracy: ± (0.1% of reading + 0.3 Torr) from 1000 to 20 Torr
± (5% of reading + 0.00025 Torr) from 20 to 0.001 Torr (Nitrogen)
± (10% of reading + 0.00025 Torr) from 0.001 to 0.0002 Torr (Nitrogen)
at ambient operating temperature without temperature/humidity
effects after 2 hours warm up followed by zero adjustment
Warm up time: Within rated accuracy at atmosphere: 30 minutes (typical)
For zero adjustment: 2 hours (typical)
Installation orientation: any
Internal volume: 3.5 cc (1/4” stub tube, other connections will be larger)
Maximum Pressure: Maximum operating: 1000 Torr
Maximum overpressure: 2000 Torr / 25 psig (no change in performance)
Burst pressure: 3000 Torr / 45 psig
Operating Temperature: -20°C to 70°C
WARNING: Operation above 60 °C ambient may result in case temperatures capable of causing
burns. Operation near the temperature extremes for more than 48 hours could result in display
degradation.
Humidity: 30 to 90 %RH, non-condensing
Thermal Zero Shift: < 3.5 mTorr (over -20 to 70°C range)
Thermal Span Shift: < 0.6% of reading above 10 Torr (over -20 to 70°C range)
< 5% of reading below 10 Torr (over -20 to 70°C range)
Leak Integrity: < 1x10-9 std. cc/s
Analog Output: 0-1 VDC, 0-5 VDC, 0-10 VDC (short-circuit protected, 1 kΩ min load)
0-20 mA, 4-20 mA (short-circuit protected, 1.2 kΩ max load)
Power Requirements: With display: 2.1 watts max. / 12 to 36 VDC (1.5 W typ. @ 24 VDC)
No display: 1.8 watts max. / 12 to 36 VDC (1.3 W typ. @ 24 VDC)
Class 2 power 150 VA max fused
NOTICE: Use of an underpowered or under-voltage supply could result in equipment damage.

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WARNING: Do not power with isolated drive circuits that are more than 36 volts above ground
potential or could reach 36 volts in the event of a fault. Failure to heed this warning could
result in serious personal injury and/or damage to the equipment.
Response Time: < 100 ms
CE Mark EN55011, EN61326, EN61010
RoHS Compliant YES
Wetted Materials: 304 and 316 stainless steel, glass, nickel, gold plated tungsten
Weight (approx.): 0.6 lb. (0.27 kg) without fitting
Set points: open-drain configuration (5 V / 5 mA max input)
Connectors: 2mm bayonet-style power jack (power)
9-pin “D” connector (power, analog signals, TTL serial)
3.5 mm TRRS jack (RS232/485 serial communications)
USB micro-B (virtual COM port for serial communications)
Accessories
1.3.1. Power Supplies
A 24VDC switching power supply (P/N 12-01-169) is available to directly power the HVG-2020B through
the 2mm bayonet jack.
1.3.2. Cables
The HVG-2020B instruments come with a 9 pin D-connector. A Hastings cable (Part # CB-AF-8-HVG9M) is
available to interface with the standard 15 pin D-connector found on Hastings power supplies. Cables
are available from Hastings in various lengths as well. A variable length cable with bare leads (Part #
CB-LDS-XXX-HVG9M) is also available.
Serial communications cables are available from Hastings (Part # CB-RS232-TRRS). These cables
connect from the 4-conductor 3.5 mm TRRS jack on top of the gauge to a standard 9-pin D connector
used for serial communication on older computers and other adaptors.
A USB cable is available from Hastings (Part # CB-USB-MICRO-B) that will connect from the Type-A
receptacle found on most computers to the Micro-B connector found on the HVG-2020B instruments.
This cable is 6 feet in length and includes ferrites for increased RF immunity.
More information about the power supplies and cables can be found on the Hastings web site:
http://www.teledyne-hi.com

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EAR99 Technology Subject to Restrictions Contained on the Cover Page Page 9 of 40
2. Installation and Setup
This section contains the necessary steps to assist in getting a new vacuum gauge into operation as quickly and
easily as possible. Please read the following thoroughly before attempting to install the instrument.
Receiving Inspection
Prior to opening, inspect for obvious signs of damage to the shipment. Immediately advise the carrier who
delivered the shipment if any damage is suspected. If the shipment has arrived intact, carefully unpack the
gauge and any accessories that have been ordered. Check each component shipped with the packing list.
Ensure that all parts are present (i.e. gauge, power supply, cables, etc.). Optional equipment or accessories
will be listed separately on the packing list.
Mechanical Connections
2.2.1. Mounting
NOTICE: The gauge should be installed in a clean and careful manner. Take care not to drop the
product and avoid impacts to prevent damage.
The HVG-2020B gauge may be mounted in any position, though care should be taken to prevent objects,
particles or condensate from dropping inside the gauge if mounted upside down.
Using bare hands to touching components that are exposed to the vacuum will result in increased desorption
rate and can possibly interfere with proper sealing.
Contamination can impair the operation of the gauge. If your vacuum environment is highly contaminated or
has unique fitting requirements, a Hastings filter or special adapter may be needed. Please contact the
Hastings Instruments Sales Department for assistance in your system configuration.
Mount in such a way as to minimize vibration.
WARNING: If devices employing gaseous electrical discharges are present in the vacuum
system, the discharge may couple dangerous high voltage through the gas in the chamber
directly to ungrounded conductive surfaces or electrical conductors. Seriously injury or death
can occur from contacting exposed ungrounded conductive surfaces/conductors at high
potential.
Ensure that the vacuum port to which the gauge is mounted is electrically grounded. It is
essential for personnel safety as well as proper operation that the envelope of the gauge be
connected to a facility ground. Vacuum connections that use an O-ring for a seal such as a KF
type flange or a quick connect fitting may electrically isolate the surfaces on the other side of
the connection. This may also occur on an NPT fitting if PTFE tape is used on the sealing
surfaces. In these conditions add a ground lug on a flange bolt to provide a ground path back
to a protective earth terminal.
WARNING: If poisonous or injurious gases have been used in the vacuum system, ensure that
all residues have been evacuated or flushed with inert gas before opening the system to install
the gauge tube.

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2.2.2. Plumbing
Mount the gauge as close as possible to the to the pressure area of interest. Long or restricted tubing will
create a pressure difference between that area and the gauge. Mounting too close to gas sources can also
affect pressure measurement.
The HVG-2020B can come with any of several vacuum connections, including: 1/8” NPT, ¼ VCR, ½” VCR, KF-
16, KF-25, 1.33” CF, 2.75” CF and ½” smooth stub tube. The tube is configured with the vacuum fitting
requested.
NOTICE: When installing the 1/8” NPT version, be certain to use the ½” wrench flats. Do not tighten
using the aluminum housing as a grip or damage may result.
WARNING: Do not exceed the pressure rating of the instrument. If operating near the maximum
operating pressure, ensure there is a pressure relief valve in the system.
Electrical Connections
WARNING: Care must be taken to avoid any high voltages that may be present when dealing
with power supplies.
2.3.1. Connector
The HVG-2020B 9 pin “D” connector pin assignments are listed here.
NOTICE: The cable length must be less than 30 meters long (unless
housed in a metal conduit) to meet CE Mark requirements.
2.3.2. Power Input
The HVG-2020B has its own internal switching power supply and requires between 12 and 36 VDC input voltage.
The +VDC supply is pin 3 and the –VDC return is pin 4. Case ground is pin 6.
NOTICE: Either the base or pin 6 must be connected to ground for proper noise immunity and to meet
CE Mark standards.
There is also a 2mm barrel connector available as a 24 VDC power jack. The center pin polarity is positive and
is internally connected to pin 3 of the “D” connector. The sleeve is internally connected to pin 4 of the “D”
connector.
The gauge requires a maximum of 2.1 watts for proper operation. Surge suppressors are recommended to
prevent power spikes reaching the instrument. Hastings power supplies satisfy these power requirements.
Pin #
1
High Setpoint
2
Low Setpoint
3
+ Power
(12
-
36 VDC)
4
Power
/Digital
Common
5
Analog Output
6
Case Ground
7
Tx
out
(TTL)
8
Analog
Common
9
Rx
in
(TTL)

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2.3.3. Analog Output
The analog signal output is configurable via digital communications. See the instrument label to determine how
the instrument was configured at the factory. In Hastings power supplies, the analog output is routed to the
display and is also available at terminals on the rear panel. If a Hastings supply is not used, the output is
available on pin 5 of the “D” connector.
The analog output is user selectable to be non-linear, linear, logarithmic or dual slope. Multiple voltage or
current ranges are available: 0-1 VDC, 0-5 VDC, 0-10 VDC (short-circuit protected, 1 kΩ min load), 0-20 mA, 4-
20 mA (short-circuit protected, 1.2 kΩ max load).
The standard output of the pressure meter is a 1 to 9 VDC signal logarithmically related to the pressure (9 VDC
= 1000 Torr, 1 VDC/decade). Other full scale and slope values are selectable/settable via the display or serial
communications. Predetermined linear and logarithmic selections are:
Options 1 to 11: Linear and Logarithmic Analog Outputs
Option Slope @ .0001
Torr
@ 1000
Torr
P(Torr)
from
V(volts) or I(mA)
V(
v
olts)
or I(mA)
from P (Torr)
01: 0-1 V Linear 0.001 V/Torr 0.0000 V 1.0000 V
𝑃
=
1000
∗
𝑉
𝑉
=
0
.
001
∗
𝑃
02: 0-5 V Linear 0.005 V/Torr 0.0000 V 5.0000 V
𝑃
=
200
∗
𝑉
𝑉
=
0
.
005
∗
𝑃
03: 0-10 V Linear 0.010 V/Torr 0.0000 V 10.0000 V
𝑃
=
100
∗
𝑉
𝑉
=
0
.
01
∗
𝑃
04: 4-20mA Linear 0.016 mA/Torr 4.000 mA 20.000 mA
𝑃
=
62
.
5
∗
𝐼
−
250
𝐼
=
(
𝑃
+
250
)
62
.
5
⁄
05: 0-20mA Linear 0.020 mA/Torr 0.000 mA 20.000 mA
𝑃
=
50
∗
𝐼
𝐼
=
0
.
02
∗
𝑃
06: 0-10V Log 1.00 V/dec 1.0000 V 8.0000 V
𝑃
=
10
(



)
𝑉
=
log

𝑃
+
5
07: 0-10V Log 1.00 V/dec 1.6249 V 8.6249 V
𝑃
=
10
(



.

)
𝑉
=
log

𝑃
+
5
.
6249
08: 0-10V Log 1.00 V/dec 2.0000 V 9.0000 V
𝑃
=
10
(



)
𝑉
=
log

𝑃
+
6
09: 0-10V Log 1.286 V/dec 1.1600 V 10.1620 V
𝑃
=
10

.

(



.

)
𝑉
=
1
.
286
log

𝑃
+
6
.
304
10: 4-20mA Log 2.00 mA/dec 6.000 mA 20.000 mA
𝑃
=
10

.

(



)
𝐼
=
2
log

𝑃
+
14
11: 0-20mA Log 2.50 mA/dec 2.500 mA 20.000 mA
𝑃
=
10

.

(



.

)
𝐼
=
2
.
5
log

𝑃
+
12
.
5
12: Non-linear n/a 0.3750 V 5.6590 V See Option 12 below
13: Dual Slope n/a 0.0005 V 10.0000 V See Option 13 below
There is also a custom defined logarithmic output. All the user needs to do is input the desired volts per
decade into S33 and the expected voltage at 1000 Torr into S32 (See Section 5.2.8). However, the analog
output must be put into the custom mode (S31 = 0x06) before it will accept the inputs from the user.
NOTICE: Predetermined logarithmic voltage selections should be used in the 0–10 VDC mode, otherwise
the output will be forced to fit that range; the slope and/or full-scale values will not be as listed. In 4-
20 mA mode, the output current will not go below 3.7 mA.

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There are two other analog output options that are available. One is a non-linear curve based on convection
gauges. The other is a dual slope output. These are described below.

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Option 12: Non-Linear Analog Output (Convection Style Curve)
Pressure to Voltage Conversion
p = 0.0001 Torr
p = 1000 Torr
v = 0.375
V
v = 5.659
V
Below 7.20 Torr
v=(a+cp+ep^2+gp^3)/(1+bp+dp^2+fp^3) volts
Above 7.20 Torr
v=(a+cp+ep^2+gp^3)/(1+bp+dp^2+fp^3+hp^4) volts
Below 7.2 Torr
Above 7.2 Torr
a
0.375
1.485409798
b
15.31570974
0.307029664
c
14.4180837
1.566833148
d
24.2920447
-
0.000228563
e
59.56106682
-
0.001397165
f
5.507480905
1.36167E
-
06
g
27.91187899
7.85644E
-
06
h
-
2.23911E
-
11
Voltage to Pressure Conversion
v = 0.375
V
v = 5.659
V
p = 0.0001 Torr
p = 1000 Torr
0.375 to 2.842 V
p=a+bv+cv^2+dv^3+ev^4+fv^5 Torr
2.842 to 4.945 V
p=(a+cv+ev^2)/(1+bv+dv^2+fv^3) Torr
4.945 to 5.659 V
p=(a+cv)/(1+bv+dv^2) Torr
0.375 to 2.842 V
2.842 to 4.945 V
4.945 to 5.659 V
a
-
0.02585
0.1031
100.624
b
0.03767
-
0.3986
-
0.37679
c
0.04563
-
0.02322
-
20.5623
d
0.1151
0.07438
0.0348656
e
-
0.04158
0.07229
f
0.008738
-
0.006866

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Option 13: Dual Slope Analog Output

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The analog output voltage is available on pin 5 and referenced to analog common on pin 8. The voltage output
may be set to 1, 5 or 10 volts full scale. The standard value is 10 volts and will have been set as such unless
another value was specified at time of order. The analog full-scale settings can be changed in the field with
digital commands.
NOTICE: The load resistance must be no less than 1 kΩ for voltage output to maintain accurate
readings.
Optional to the standard voltage output is the 0-20 mA or 4-20 mA current output that is proportional to
pressure. The current loop output is useful for remote applications where pickup noise could substantially
affect the stability of the voltage output. The current loop signal replaces the voltage output on pin 5 of the D”
connector and is returned on pin 8.
NOTICE: The loop load must be less than 1.2 kΩ. Failure to meet this condition will cause failure of the
loop transmitter. Wiring diagrams for power and 4-20mA signals are shown below.
NOTICE: The power requirements are greater when using 0-20mA and 4-20mA output signals.
NOTE: 0-20mA cannot indicate a negative zero offset.
4 – 20 mA wiring diagram w/ unipolar supply

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2.3.4. Setpoints
The HVG-2020B has two open-drain setpoints available on the 9 pin D connector. The Hi setpoint will be active
when the pressure is above its set value and the Lo setpoint will be active when the pressure is below its set
value. There is a small amount of hysteresis built into the settings. Once a setpoint is activated, the pressure
must go 10% beyond that value in the opposite direction to deactivate when below 10 Torr. Above 10 Torr, the
pressure must go 1 Torr beyond the setpoint value.
The set point values can be changed via the display (Setpoint View, Section 3.2) or serial communications (see
S20 and S21 commands). The setpoints will also show on the Bar Graph View as up and down arrows.
NOTICE: To utilize the open drain setpoint pins, external pull-up resistors larger than 1 kΩ are required.
Do not apply more than 5 volts to the setpoint pins.

HVG-2020B Instruction Manual
EAR99 Technology Subject to Restrictions Contained on the Cover Page Page 18 of 40
2.3.5. Serial Connection
The HVG-2020B has a 4-conductor TRRS 3.5 mm jack on the top of the instrument for digital communication.
To daisy chain instruments on a RS485 bus, Y-splitters of the 4-conductor variety are available. The HVG-2020B
can be configured to operate with either RS232 or RS485 signals via digital command or via the display.
Hastings uses a full duplex configuration. See the tables below for the standard pin-out.
If making up a cable to interface from the TRRS 3.5 mm jack connector to a
standard PC 9-pin serial port (RS232), use the connections as listed here.
NOTICE: The serial cable length must be less than 30 meters long (unless housed
in a metal conduit) to meet CE Mark requirements.
The HVG-2020B uses RS485 receivers that are protected from bus over-voltages and will
not be damaged if connected to a bus without a driver or pull up resistors. The option to
enable 120-ohm termination resistors is available via the display or digital command.
They should be used if the instrument is the last one in a long cable length (prevents
miscommunications due to reflections). This is not normally necessary for short cables.
Do not have more than one instrument with these resistors enabled on any one cable run
as this will load down the cable. Hastings ships RS485 instruments without the resistors
enabled.
The default port set-up is 19.2K baud, 8 data bits, 1 stop bit, no parity and no flow control. A “carriage return”
signals the end of command input. The end of a response message from the HVG-2020B is signaled by a “>”
character. See Serial Communications section later in this manual for more information.
2.3.6. USB Connection
A USB micro-B connector is available that will implement a serial port interface. It will appear in the “Devices
and Printers” list as “Teledyne Hastings Digital” along with its assigned COM port number. The serial port
parameters are: 8 data bits, No Flow Control and 1 stop bit. The baud rate does not matter.
Only Windows 7 and 10 are supported. A device driver (THI_D300.inf) is needed for Windows 7, but not for
Windows 10.
2.3.7. TTL Serial Connection
TTL Serial output is available on the 9-pin D connector pins 7 (Tx out) and 9 (Rx in). The voltage levels are near
3.3 V for logic high and near 0 V for logic low. To communicate using a computer serial port, a TTL-to-serial
converter is required to raise the signal voltage levels to those required for RS232 communications.
COMMUNICATIONS CABLE PIN
-
OUT
Pin#
RS232
RS485
1
(Sleeve)
Common
TX+ (TDB)
2
(Tip)
TX
TX
-
(TDA)
3
(Ring 1)
RX
RX
-
(RDA)
4
(Ring 2)
NC
RX+
(RDB)
TRRS
D9
Female
NC
1
2
2
3
3
NC
4
1
5
NC
6
NC
7
NC
8
NC
9

HVG-2020B Instruction Manual
EAR99 Technology Subject to Restrictions Contained on the Cover Page Page 19 of 40
Push-button Operation
On top of the HVG-2020B instrument, there is a push-button that serves to
reset the zero by pressing and holding it for at least 3 seconds when the
pressure is known to be well below 0.1 mTorr.
For HVG-2020B instruments without a display, the push-button has an
additional function. To toggle RS232 and RS485 communications, press and
hold the button before applying power, then apply power and continue holding button until both LEDs blink
rapidly.
LED Operation
The HVG-2020B will go through an internal self-check upon power up and go into normal operation. The LEDs
on top of the unit indicate the state of the device as follows:
System State
Status LED
Vacuum
LED
Pressure > 1000 Torr Steady Green Flash Yellow at 1 sec rate
Pressure > 800 Torr Steady Green Steady Yellow
Pressure near 760 Torr Steady Green Steady Green
Pressure < 700 Torr Steady Green
Flash Green at
1 sec rate,
Duty cycle proportional to pressure
Pressure < 1 Torr Steady Green Short flash green at 1 sec rate
Pressure < 0.01 Torr Steady Green Short flash green at 2 sec rate
Main Board Comm Error
Flash Red at
2
s
ec
r
ate,
Opposite of Vacuum LED
Flash Red at
2
sec
r
ate,
Opposite of Status LED
Piezo Sensor Failure Steady Red Steady Red
Pirani Sensor Failure Steady Red Flash Red at 2 sec rate
Calibrate Mode
Flash Green at 1
s
ec
r
ate,
In Synch with
Vacuum
LED
Flash
Green at 1 s
ec
r
ate,
In Synch with Status LED
Toggle RS-232/485
Flash Green
at 1/8
s
ec
r
ate,
Opposite of
Vacuum
LED
Flash Green at 1/8 s
ec
r
ate,
Opposite of
Status
LED
Push-button Force zero
Flash Green
at 1/8
s
ec
r
ate,
In Synch with
Vacuum
LED
Flash Gre
en
at 1/8
s
ec
r
ate,
In Synch with
Status
LED
Push-button Adjust Zero Steady Green Flash Green at 1/8 sec rate

HVG-2020B Instruction Manual
EAR99 Technology Subject to Restrictions Contained on the Cover Page Page 20 of 40
Quick Start
1. Unpack and inspect all items for any obvious signs of damage due to shipment. Immediately advise the
carrier who delivered the shipment if any damage is suspected.
2. Wire the 9-pin “D” connector according to cable pinout using 24 AWG or other suitable wire.
3. Using a unipolar DC Power Supply, set the desired operating voltage within the range of 12 VDC to 36
VDC.
4. Transducer tube may be installed in any orientation. However, if condensation is likely to occur, then
the tube port should be orientated downward.
5. When installing 1/8” NPT style transducer tube, use the ½” wrench flats.
6. Attach cable.
7. With the vacuum chamber at atmosphere, turn on the power supply. Gauge is now reading pressure.
8. For best accuracy, the gauge should now be zeroed. To do this, pump the vacuum system down to less
than 1x10-4 Torr. Ideally the gauge should be powered for two hours before setting the zero.
9. To set the zero, press the menu icon, scroll to the Set Zero menu page and press the EDIT button.
Alternatively, press and hold the Zero button until the LEDs flash.