Honeywell HPB User manual

Chipsmall Limited consists of a professional team with an average of over 10 year of expertise in the distribution
of electronic components. Based in Hongkong, we have already established firm and mutual-benefit business
relationships with customers from,Europe,America and south Asia,supplying obsolete and hard-to-find components
to meet their specific needs.
With the principle of “Quality Parts,Customers Priority,Honest Operation,and Considerate Service”,our business
mainly focus on the distribution of electronic components. Line cards we deal with include
Microchip,ALPS,ROHM,Xilinx,Pulse,ON,Everlight and Freescale. Main products comprise
IC,Modules,Potentiometer,IC Socket,Relay,Connector.Our parts cover such applications as commercial,industrial,
and automotives areas.
We are looking forward to setting up business relationship with you and hope to provide you with the best service
and solution. Let us make a better world for our industry!
Contact us
Tel: [phone] Fax: [phone]
Email & Skype: [email protected]om Web: www.chipsmall.com
Address: A1208, Overseas Decoration Building, #122 Zhenhua RD., Futian, Shenzhen, China
  

HPB\HPA User Manual
1 www.honeywell.com
Honeywell Precision Barometer
HPB and HPA User’s Manual
RS-232 and RS-485 Output

HPB/HPA User Manual
2 www.honeywell.com
Table of Contents
0 USER’S MANUAL CONTENT 1
1 INTRODUCTION 2
1.1 PRODUCT OVERVIEW 2
1.2 HARDWARE DESCRIPTION 2
2 GETTING STARTED 3
2.1 OVERVIEW 3
2.2 EQUIPMENT NEEDED 3
2.3 TERMINAL PROGRAM SETTINGS 3
2.4 INITIAL TURN-ON RESPONSE 4
2.5 COMMAND FORMAT 4
2.6 STEP-BY-STEP EXAMPLES (Only for single HPB connection) 4
2.7 COMMAND FUNCTIONAL GROUPS 6
3 COMMANDS—QUICK REFERENCE 9
4 FUNCTIONAL OPERATION 12
4.1 OVERVIEW 12
4.2 WHAT IS INTEGRATION? 12
4.3 PRESSURE READING CONTROL 13
4.4 CUSTOMIZED PRESSURE RANGE 15
4.5 COMMAND ILLUSTRATIONS 16
4.6 PRESSURE READING DECIMAL POSITION 19
4.7 HPB ADDRESSING 20
5 COMMANDS 24
5.1 COMMAND FORMAT 24
5.2 INFORMATION REQUEST COMMANDS 24
5.3 ACTION DIRECTING COMMANDS 25
5.4 COMMAND REPLIES –GENERAL 25
5.5 ASCII FORMAT REPLIES 26
5.6 BINARY FORMAT REPLIES 27
5.7 COMMAND AND REPLY SEQUENCING 29
5.8 COMMAND ERRORS 30
5.9 COMMAND SUMMARY TABLE 31
5.10 COMMAND DESCRIPTIONS 33
6 ELECTRICAL CONNECTIONS 61
7 TIMING DIAGRAMS 63
8 SPECIFICATIONS 66
9 DIMENSIONS 68

HPB\HPA User Manual
www.honeywell.com 3
Figures
Figure 4.1—HPB Block Diagram 12
Figure 4.2—Pressure Reading Control 14
Figure 4.3—Custom Slope (X=) Options 15
Figure 4.4—Custom Offset (Z=) Options 15
Figure 4.5—Integration (I=) Command, Example 1 16
Figure 4.6—Integration (I=) Command, Example 2 16
Figure 4.7—S2 Speed Shift Command Example 17
Figure 4.8—S5 Speed Shift Command Example 17
Figure 4.9a—Deadband and Sensitivity (DS) Command Examples 18
Figure 4.9b—Deadband and Sensitivity (DS) Command Examples 18
Figure 4.10—Idle Count (IC) Command Example 18
Figure 4.11—Synchronize Integration Cycles (SI) Command Example 19
Figure 4.12—HPB RS-232 Ring Network 20
Figure 4.13—HPB RS-485 Multidrop Network 22
Figure 5.1—Single HPB Command and Reply 29
Figure 5.2—Multiple HPB Network Command and Replies 30
Figure 6.1—HPB RS-232/485 Electrical Connector Pin Assignments 61
Figure 6.2—Connection for RS-232 Operation 61
Figure 6.3—Connection for RS-485 Operation 62
Figure 7.1—Default Single Pressure Reading Timing Diagram 63
Figure 7.2—Default Continuous Pressure Reading Timing Diagram 63
Figure 7.3—Continuous Pressure (with IC = 1) Timing Diagram 63
Figure 7.4—Timing Diagram for 20 Readings Per Second 64
Figure 7.5—Timing Diagram for 50 Readings Per Second 64
Figure 7.6—Timing Diagram for 120 Readings Per Second 64
Figure 9.1—HPB Case Outline Standard 68
Figure 9.2—Electrical Connector 68

HPB/HPA User Manual
4 www.honeywell.com
Tables
Table 1.1—Various Digital Modes 2
Table 4.1—Decimal Place Locations for Pressure Readings 19
Table 5.1—Header Description for Binary Format Pressure Readings 27
Table 5.2—Binary Format Character Codes 27
Table 5.3—Command List 32
Table 5.4—Factory Default Command Responses 34
Table 5.5—Display Units Options 41
Table 7.1—Transmission Times at Selected Baud Rate 65
Table 7.2—Number of Bytes in Various Replies 65
Table 9.1—ASCII Conversion Table, Decimal to Hexadecimal 69
Table 9.2—RS-232 Standard Pin Connections 69
Table 9.3—Electrical Signal Levels 69

HPB\HPA User Manual
www.honeywell.com 5
0 USER’S MANUAL CONTENT
This user‘s manual is divided into the following sections.
Section 1 Introduction—Product overview and hardware description.
Section 2 Getting Started—Lists equipment and procedures necessary to operate the HPB and
provides a few simple command examples, which will get first-time users acquainted
with the command structure.
Section 3 Commands: Quick Reference—A brief description of each command with typical HPB
input and response examples.
Section 4 Functional Operation
Section 5 Commands—Contains a detailed description of the command structure, functional
groupings and all user commands.
Section 6 Electrical Connections—Contains wiring diagrams for various HPB electrical
connections.
Section 7 Timing Diagrams—Illustrates RS-232 serial port timing for command and reply
interaction.
Section 8 Specifications—Contains electrical and environmental specifications.
Section 9 Dimensions—Contains a case outline of the HPB
It is suggested that the first-time user read the ―Getting Started‖ section to be sure the necessary items are on hand.
Be sure to connect a source of pressure that matches the transducer range.

HPB/HPA User Manual
6 www.honeywell.com
1 Introduction
1.1 PRODUCT OVERVIEW
The Honeywell Precision Barometer RS-232 and Honeywell Precision Barometer RS-485* (HPB) provides high
accuracy absolute pressure readings in digital form. The first-time user will be able to use the HPB within minutes,
yet capability exists to configure the HPB for optimum performance in specific applications.
The heart of the HPB measuring system is a silicon piezoresistive sensor, which contains both pressure and
temperature-sensitive elements. Digital signals representing temperature and pressure are processed by a
microprocessor to produce fully temperature compensated and calibrated pressure readings over the entire -40 to
85°C temperature range.
Any computer having a serial port and terminal emulation software can be connected to the HPB to allow the user
to select baud rates, sample rates, readout resolution, units of pressure and other choices. RS-485 versions
require an RS-485 to RS-232 converter or and RS-485 port on the computer. User selected functions are set
through the digital interface. The selected functions may either be used temporarily, until the HPB is powered
down, or may be stored in the internal EEPROM to automatically configure the HPB each time power is applied.
The HPB receives commands and sends data from either an RS-232 port or a multidrop RS-485 port. Using the
RS-232 type HPB, up to 89 units can be connected in a ring configuration to a single serial port of a computer. The RS-485
type HPB allows up to 89 HPBs to be connected to a two-wire multidrop bus, when bus repeaters are used to
satisfy the RS-485 bus electrical requirements. Group (multicast) addressing allows up to nine groups of HPBs to
be addressed with a single command. Global (broadcast) addressing will send a command to all HPBs on the
serial bus.
1.2 HARDWARE DESCRIPTION
See Sections 8 and 9.
* For simplicity, references throughout this manual HPB-RS-232, HPB-RS-485, HPA-RS-232 & HPA-RS-485 have been
shortened to HPB.

HPB\HPA User Manual
www.honeywell.com 7
2 GETTING STARTED
2.1 OVERVIEW
The first-time user should approach the HPB in a manner analogous to using a word processor program; i.e.,
many features are available but one may begin by using those of interest at the moment. Section 2.7 of this
manual lists command features by functional groups to assist in this selection. When shipped from the
factory, the default settings provide a pressure transducer that will be usable for many applications. Once the
user is familiar with the performance and command structure, changes may be made and stored using the
‗Store Parameters‘ (SP) command. Once stored, the new default settings are activated each time the HPB is
powered up. This tailors the personality of the HPB to meet the needs of a particular application.
2.2 EQUIPMENT NEEDED
To prepare the HPB for operation, four items are needed:
• A mating connector with proper wiring connections (see connector part number and wiring diagram in
Section 6—Electrical Connections);
• A DC power supply;
• A source of pressure that is properly matched to the range of the HPB.
• A computer, or host processor, having an RS-232 or RS-485 serial port and terminal program software
such as HYPERTERMINAL . These programs are normally used to interface to a modem. The wiring diagram
designates which HPB pins must connect to the computer ―send‖, ―receive‖ and ―common‖ pins for proper
communications. Some computers may not have an RS-232 or RS-485 serial port connection identical to the
one shown in Section 6, making it necessary to adapt the HPB connections to that particular computer. A link
to Honeywell demonstration software is available at www.pressuresensing.com.
2.3 TERMINAL PROGRAM SETTINGS
• Enter the following settings in the terminal program:
Baud Rate ..... 9600
Start Bits ..... 1
Data Bits ..... 8
Stop Bits ..... 1
Parity ..... None
• Attach a line feed to the carriage return.
• Turn the local echo ON.
When shipped from the factory, the HPB is set to a baud rate of 9600, 1 start bit, 8 data bits with no parity
and one stop bit. If the baud rate has been subsequently changed, and is unknown, it will be necessary to
search all baud rate values to reestablish communication. See the BP command description in Section 5.10
of this manual for possible settings.
2.4 INITIAL TURN-ON RESPONSE
Once the wiring connections and terminal program settings are complete, the HPB will automatically send
the following response (or similar to) when power is applied. This reply will be generated any time power is
applied to the HPB.
Typical Reply:
?01HPB_ _ 1200mBAR RS-232
?00HPB_ _1200mBAR RS-485
The ―?01‖ or ―?00‖ indicates a default address device called a ―null address‖. This HPB has not yet been
assigned an ID number so it assumes the null address.

HPB/HPA User Manual
8 www.honeywell.com
2.5 COMMAND FORMAT
Any command interaction with the HPB requires electrical connection to the RS-232 or RS-485 serial
communications pins. There are two basic types of commands: action directing commands and information
requesting commands. Theses commands are described in Section 5.
Typical HPB commands have the form *ddcc = nnn <cr>
Where: *
dd
cc
=
nnn
<cr>
is the command header character
is the decimal address of the HPB
is a command (refer to Commands –Section 5 for a complete
description
of commands)
equal sign (required in some commands)
additional characters (required in some commands)
carriage return is required to end all commands
(do not type, press the ENTER/RETURN key)
2.6 STEP-BY-STEP EXAMPLES (Only for single HPB connection)
The following examples assume that the reader has followed them in order.
•READ SINGLE PRESSURE
Once the HPB is powered up and connected to a computer, enter the following command:
Type: *00P1 <cr>
Response:
?01CP=15.458 (for RS-232)
?00CP=15.458 (for RS-485)
where * indicates the start of a command
00 is the null address of the HPB (see note below)
P1 is the command to read the most current pressure
Note: The ―?‖ indicates a response from a null address HPB – one which has not been assigned a
device ID. A null address, 00, is coded into each HPB at the factory. When an RS-232 null address HPB
responds, it adds one to its address, hence, the response ‗01‘. Refer to the ID command in Appendix A
for a description of addresses and responses.
In the reply, the ―01‖ identifies the individual unit address (range 01-89). The ―CP=15.458‖ indicates a
compensated pressure of 15.458 psi. Your unit may not show this specific reading, depending on the
applied pressure it is measuring.

HPB\HPA User Manual
www.honeywell.com 9
•SET DEVICE ID
To give the HPB an assigned address of 01 up to 89, enter the following commands:
Type: *00WE <cr>
Type: *00ID=01 <cr>
This enables the HPB to change a parameter in RAM
This sets the null addressed HPB to device ID=01.
Note: The device ID is now used in the command input
Type: *01S= <cr> Response: #01S=00052036 (serial number test)
where:
The ―#‖ now replaces the ―?‖ in the header and indicates the HPB response
is from an address assigned unit.
* indicates the start of a command
00 is the null address of the HPB
WE is the command to enable a configuration parameter change
ID is the command to change the device address
01 is the assigned HPB address for this example
S= is the command to read the serial number
•READ PRODUCTION DATE
To read the production date, enter the following command:
Type: *01P= <cr>
Response:
#01P=11/15/02
(Actual responce depends on production date of device being used.)
•READ CONTINUOUS PRESSURE
For continuous pressure readings at the factory set default rate of 5 per second, enter the following
command:
Type: *01P2 <cr> This enables a continuous stream of compensated pressure readings to flow
into the terminal program.
Type: $*99IN <cr> This is the best way to stop the continuous pressure reading commands.
The ‗$‘ character temporarily stops, or suspends, either the continuous
pressure or temperature readings. The *99IN command stops the
continuous pressure readings.
•CHANGE TO A NEW SAMPLE RATE
Enter the following command:
Type: *01WE <cr> This enables the HPB RAM to accept a changed parameter.
Type: *01I=M20<cr> This sets the integration time to value 20, which corresponds to an output
sample every 2 seconds.
The sample rate will change to one every 2 seconds. I= is an abbreviation for Integration time which
determines how long to accumulate pressure samples between readings. Each integration period
gathers the data for one pressure reading output (see Section 4.2 What is integration?). The range of
integration times can be set by specifying readings per second (I=R45 for 45 readings/sec) or time delay
in 100 millisecond intervals (I=M60 for 6 seconds). The factory set integration time is 5 samples per
second (I=M2).
The output data rate can also be altered by use of the idle count (IC) command or by using the reading
rate (RR) command in conjunction with the operating mode (OP) command. See Section 4 for
description of these commands.

HPB/HPA User Manual
10 www.honeywell.com
•REPEAT THE READ CONTINUOUS PRESSURE STEP ABOVE
Notice the slower output rate of one sample every 2 seconds.
•TRY OTHER COMMANDS
Experiment with other commands to become familiar with the command structures. A short overview of
each command with input and response examples is shown in Section 3 Commands –Quick Reference.
See Section 5—Commands for complete command descriptions. Re-apply the power or send an
IN=RESET command to revert to EEPROM default settings. Until an SP=ALL command is executed, no
changes will be stored in the EEPROM.
2.7 COMMAND FUNCTIONAL GROUPS
•PRESSURE DISPLAY UNITS —HPB reads out psi, in wc, mm Hg, etc.
DU Set pressure units for output readings—any one of 13 common units (See Section 8)
U= Specify a user supplied unit of measure
•TEMPERATURE
T1 Single °C
T2 Continuous °C
T3 Single °F
T4 Continuous °F
•RS-232/RS-485 BUS PARAMETERS
BP Changes baud rate and parity
ID Assign device ID and group addresses
M= Select alternate message Headers [RS-485 only]
SI Synchronize Integration cycles among units [RS-485 only]
TO Set Transceiver Operating parameters
•OUTPUT READING AND RATE—Speed up or slow down output rate
Single Reading Commands
P1 Single pressure reading...ASCII format
P3 Single pressure reading...binary format
T1 Single temperature reading...°C
T3 Single temperature reading...°F
Continuous Readings Commands
P2 Continuous pressure readings...ASCII format
P4 Continuous pressure readings...binary format
T2 Continuous temperature readings...°C
T4 Continuous temperature readings...°F
Integration Time Commands —Changes pressure reading response time
DS Set deadband and sensitivity parameters
I= Set pressure integration time, and sampling rate
S2 Set threshold level for 2X speed shift
S5 Set threshold level for output within any 50 msec period
SI Synchronize pressure Integration cycles
Idle Count Command —Changes pressure reading response time
IC Set number of idle integration cycles
Reading Response To Changes In Input Pressure—Filters small changes
S2 Set threshold level for 2X speed shift
S5 Set threshold level for output within any 50 msec period
RR Set number of identical readings to skip
OP Transmit all readings or only changed readings

HPB\HPA User Manual
www.honeywell.com 11
•FORMAT PRESSURE READINGS—Changes data length into host processor
Binary Format Commands
P3 Single RS-232 pressure...binary format
P4 Continuous RS-232 pressure...binary format
OP Set operating mode...binary format checksum...set signed or extended binary output format
ASCII Format Commands
All readings, except P3 and P4, are ASCII format readings.
OP Set operating mode...all readings or only changed readings
•START-UP PARAMETERS—Sets the HPB configuration after power is applied
WE Enable parameter writes to the RAM or EEPROM
SP Store RAM parameters to the EEPROM for startup
MO Specify the power-up message and operating mode
•PRESSURE NOISE REDUCTION—Reduces pressure noise signals
DS Set deadband and sensitivity parameters
•DIAGNOSTIC AND RESET CONTROL
IN Performs a software reset of microprocessor
RS Read status of error indicators
CK Performs and provides the result of EEPROM checksum
OP Use pressure reading checksum for binary format
•USER AND STARTUP MESSAGES
A= Store 8 characters of user supplied data
B= Store 8 characters of user supplied data
C= Store 8 characters of user supplied data, which can be configured as a watchdog or reset
message
D= Store 8 characters of user supplied data, which can be configured as a watchdog or reset message
MO Specify the startup header selection
•HPB UNIT INFORMATION
P= HPB production date
S= HPB serial number
V= HPB software version number
ID Assign device ID and group addresses
M= Read the maximum full scale pressure limit allowed
•CUSTOMIZE PRESSURE WINDOW
F= Customize the full scale pressure limit
X= Set the slope ―m‖ parameter for user input mx+b control
Z= Set the offset ―b‖ parameter for user input mx+b control
3 COMMANDS—QUICK REFERENCE

HPB/HPA User Manual
12 www.honeywell.com
(1) A carriage return, <cr>, should follow each input. If the HPB has an established address of 12, for instance, then begin the command
with *12..instead of *00...
(2) The responses shown here begin with ?01.. and are for a null address HPB. That is, an HPB that has not yet established unit identification
(see ID command). If the HPB has an assigned address of 23, for instance, the response will begin with #23.. instead of ?01...
Note: See Section 5.10 for complete command descriptions.

HPB\HPA User Manual
www.honeywell.com 13
Note: See Section 5.10 for complete command descriptions.

HPB/HPA User Manual
14 www.honeywell.com
Note: See Section 5.10 for complete command descriptions.

HPB\HPA User Manual
www.honeywell.com 15
4 FUNCTIONAL OPERATION
4.1 OVERVIEW
The HPB is based on a silicon piezoresistive sensor coupled with a microprocessor and other electronic
circuitry. The piezoresistive sensor contains both pressure sensitive and temperature sensitive elements
which, when modeled over a matrix of pressures and temperatures at the factory, provides a digitally
compensated pressure reading. The HPB has an accuracy of 0.03% of full scale (FS) over a -40 to +85°C
temperature range. This accuracy is achieved by compensation algorithms in the microprocessor. Because
of the internal digital circuitry, having a digital output capability is straight forward. The digital readings are transmitted
via RS-485 signals or RS-232 signals, which are commonly available on most personal computers. When
connected to a computer, the user can modify the pressure reading rate, integration times, units of pressure,
thresholds for deadbands and more.
Figure 4.1—HPB Block Diagram
The HPB can be tailored to specific application requirements. Configuration information is sent to, or read
from, the HPB by user command messages over the serial port. Any configuration parameter that can be
changed by a command may be retrieved by use of that same command except baud rate or parity.
Commands used to change parameters must be preceded by an enabling command (WE or NE), but
commands used to retrieve information do not require an enable. All configuration changes are stored in the
HPB RAM for immediate use until power is removed. These configuration changes are only made permanent
in the EEPROM when the user executes the Write Enable (WE) command followed by the EEPROM Store
Parameters (SP) command. Exceptions to this are the A=, B=, C=, and D= commands which are
immediately stored to EEPROM if preceded by the WE command.
4.2 WHAT IS INTEGRATION?
The input pressure is converted to an analog electrical signal at the pressure sensor. This signal feeds into a
delta-sigma analog-to-digital (A/D) converter where it is changed into a digital signal representing the
pressure value. During the A/D conversion cycle, the signal is integrated over time. That is, the pressure
reading is averaged (integrated) over the A/D conversion cycle so the resultant digital value is the summation
of the average pressures observed during the cycle. This conversion cycle is controlled by the user with the
Deadband and Sensitivity (DS), Synchronization Integration (SI), Idle Count (IC), and Integration (I=)
commands.

HPB/HPA User Manual
16 www.honeywell.com
4.3 PRESSURE READING CONTROL
The HPB commands allow considerable flexibility in tailoring pressure acquisition times, sample windows,
thresholds, and output rates. These are controlled by 7 commands: Deadband and Sensitivity (DS), Integration
(I=), Speed shift (S2), Speed shift at 50msec intervals (S5), Idle Count (IC), Reading Rate (RR), and OPerating
mode (OP). Figure 4.2 illustrates how the user may control these attributes in three ways:
First, the internal analog-to-digital converter integration time may be controlled over a range of 1 sample every 12
seconds up to 120 samples per second. This is controlled using the ‗Integration‘ (I=) command. The integration
time is used to control the A/D integration cycle that allow noisy pressure inputs to be filtered, or averaged, over a
selected period of time. See Figures 4.5 and 4.6. The integration time can be set within a range of 1 to 120
samples/sec using the I=Rn form or a range of 100msec to 12 sec/sample using the I=Mn form. The values for ‗n‘ range from
1 to 120 for both the rate (Rn) form and the millisecond (Mn) form.
The speed shift commands can only be enabled when the integration time is set using the I=Mn form. When
enabled, the thresholds for pressure change can be set that cause the output rate to double (S2) or update at 50
msec intervals (S5). When the change of input pressure reaches or exceeds the threshold, the sample rate shifts
to the higher rate.
Second, the integration cycles may be spaced with idle periods that cause pressure reading times to increase to
as often as one every 51 minutes. The Idle Count (IC) command will insert, or skip, from 0 to 255 idle periods
equal to the integration time. If the integration time is set to the maximum, 12 sec/sample, and an idle count of
255 is selected, then the time between samples = 12 sec. x 256 = 51.2 minutes.
Third, the reading rate may be controlled so pressure readings are obtained only when pressure changes occur.
The Reading Rate (RR) command can be set to only output changed readings, or to skip from 100 to 1000
identical readings. The Operating Mode command (OP) can be set to output every reading or to only output
readings when a pressure change occurs. The Deadband setting in the DS command can filter a small pressure change by
not allowing the pressure reading to vary as long as it remains within the deadband limits. This controls the
sensitivity to change of the RR and OP command modes when the ‗output only when pressure changes‘ options
are selected. If the pressure signal is stable within the deadband limit, then the pressure reading time can be
increased up to 1000 times the integration time by using the RR command.

HPB\HPA User Manual www.honeywell.com 17
Figure 4.2—Pressure Reading Control
Shaded blocks represent command codes executed in the microprocessor
• Single or Continuous
• ASCII or Binary
Pressure Values
P1, P2, P3, P4
Pressure
if c = 0 then no wait cycles
if c = 1 - 255 then add 'c' wait
cycles between inputs
IC = c
(IC=0 factory default)
Idle Count
if r = 0 then output every input
if r = 1 - 10 then skip r x 100
identical readings
RR = r
(RR=00 factory default)
Reading Rate
if d = A then output every input
if d = U then output only changes
if p = X then no watchdog timer
if p = W then use watchdog timer
For binary format mode:
if m = N then no checksum
if m = C then use checksum
if n = S then use standard format
if n = E then use extended format
OP
= d m n p
(OP=ANEX factory default)
Operating Mode
HPB Pressure Rate Conditioning
DS = dd Sn
(DS=00S0 factory default)
Deadband and Sensitivity
User Compensation
Pressure
Input
RS-232 or
RS-485
Driver
TD
Digital
Outputs
I
= Rn or
I
= Mn
(
I
=M002 factory default)
range for n value: 1-120
Rn: n readings/sec
Mn: n x 100 msec/reading
Integration Time
if
I
= Rn
if
I
= Mn
A/D
Converter
Dead Band
DB = n x dd x 0.005% FS range
(dd= 0 - 60, n=1, 2, 4, or 8)
User Compensation
Press. = mX + b
(
X=
m,
Z=
b)
X=nn, Z=nn
(X=1.000 factory default)
Delay
Output Control
Output Control
Output Mode
and Format
Integration
Display Units
Display Units
Scalar

HPB/HPA User Manual
18 www.honeywell.com
4.4 CUSTOMIZED PRESSURE RANGE
The user can adjust the pressure vs. output value transfer curve using the X=, Z= and F= commands. The X=
command adjusts the slope of the pressure output curve. The Z= command adjusts the offset of the pressure
output curve. The range of adjustment for X= and Z= commands is ±0.6%FS in 0.005% increments. The F=
command can change the full scale pressure span to any value between 50% and 100% of the factory specified
range (M=). The purpose of these commands is to allow the user to provide compensation for the pressure values specific
to an application. This type of adjustment is made after the HPB temperature compensates the pressure reading
according to the factory calibration. The user-supplied values (X=, Z=) are used as an mx+b correction. The X=
command supplies the slope adjustment, or ‗m‘, value and the Z= command supplies the offset adjustment, or
‗b‘, value.
Figures 4.3 and 4.4 illustrate these commands.
Figure 4.3—Custom Slope (X=) Options Figure 4.4—Custom Offset (Z=) Options
The user compensated pressure output can be expressed in terms of X= slope values ‗m‘ where m=0 to ±120.
The offset value, Z=, can be expressed as ‗b‘ where b=0 to ±120.
Pressure Output = [(1 + mx 0.00005) x Pressure Reading] + [(bx 0.00005) x (full scale)]
The F= command is used in conjunction with the X= and Z= command to customize the full scale range and user
compensation of the HPB. The F= command allows the user to reduce the full scale range of the HPB as much as
one-half the factory FS value. The F= command value can have up to 5 significant digits with a decimal point.
Enter an F=0 command to disable this function and return to the factory default (M=) full scale value. Using the
F= command, the maximum allowable full scale pressure is the M= value and the minimum allowable FS
pressure is (0.5 x the M= value). The new F= value becomes the standard FS number used for other commands
and range calculations. (Note that the accuracy specification is always referenced to the factory (M=) full scale
value.) For example, to customize the full scale range of a 1200 mBar (900mm Mercury - mmhg) device to 800
mmhg, first select the desired display units using the DU command. Enter the command *ddWE followed by a
*ddDU=mmhg. Then enter a *ddWE followed by a *ddF=800. The full scale pressure for this unit is now 800
mmhg.

HPB\HPA User Manual
www.honeywell.com 19
4.5 COMMAND ILLUSTRATIONS
The figures below illustrate the commands that affect the pressure output rate. Figure 4.5 shows a varying pressure
signal having a reading integration time of 200 msec. If the small variations on the pressure signal are considered
noise and are undesirable, increase the integration time to time-average the pressure signal, and filter out the noise.
Figure 4.5—Integration (I=) Command, Example 1
Figure 4.6 shows the same pressure signal with a 1 second integration time reducing the noise variations on
the output readings. Of course, the penalty for doing this is reducing the response time to rapidly changing
pressures that are not considered noise.
Figure 4.6—Integration (I=) Command, Example 2
Figures 4.7 and 4.8 illustrate rapid pressure changes using the S2 and S5 commands. The Speed Shift
commands (S2, S5) allow the tracking of rapid changes while sampling less often when pressures are slowly
changing. A threshold is set independently for the S2 and S5 commands that tell the HPB when to begin
outputting samples at the higher rate. The S2 command causes the output rate to double. The S5 command
causes the readings to be output at 50 msec intervals synchronous with the normal reading rates.