halstrup-walcher P26 User manual

P26 Instruction Manual
Differential Pressure
Transmitter
halstrup - walcher GmbH
Stegener Straße 10
D-79199 Kirchzarten
Phone:[phone]
Fax: [phone]
Email: [e-mail]
Internet: www.halstrup-walcher.de
Document 7100.004084 10/2017

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Table of Content:
1 Purpose of instruction manual.............................................................................................5
2 Safety precautions...............................................................................................................6
2.1 Appropriate use..............................................................................................................6
2.2 Shipping, assembly, electrical connections and start-up.................................................6
2.3 Troubleshooting, maintenance, repairs, disposal............................................................7
2.4 Symbols.........................................................................................................................7
3 Instrument description.........................................................................................................8
3.1 Functions .......................................................................................................................8
3.2 User interfaces...............................................................................................................9
3.3 Internal connections and buttons..................................................................................10
3.4 Front view ....................................................................................................................13
4 Zero-point calibration cycle................................................................................................14
4.1 External zero-point calibration (optional) ......................................................................14
5 Overpressure protection....................................................................................................14
6 Display (optional)...............................................................................................................14
7 Menu (optional) .................................................................................................................15
7.1 Display.........................................................................................................................15
7.2 Scale............................................................................................................................15
7.2.1 Pressure.................................................................................................................16
7.2.1.1 Top...............................................................................................................16
7.2.1.2 Bottom..........................................................................................................16
7.2.1.3 Units.............................................................................................................16
7.2.2 Volume flow............................................................................................................16
7.2.2.1 Value............................................................................................................17
7.2.2.2 Units.............................................................................................................17
7.2.3 Mass flow................................................................................................................17
7.2.3.1 Value............................................................................................................17
7.2.3.2 Units.............................................................................................................17
7.2.4 Flow rate.................................................................................................................17
7.2.4.1 Value............................................................................................................17
7.2.4.2 Units.............................................................................................................17
7.3 Air consumption function (option available from firmware version 3.0) .........................18
7.3.1 Mode.......................................................................................................................18
7.3.1.1 Off................................................................................................................18
7.3.1.2 Σ(ΔP >0).......................................................................................................18
7.3.1.3 Σ(ΔP)............................................................................................................18

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7.3.1.4 Σ(abs ΔP).....................................................................................................18
7.3.2 Mass/Pulse or Vol./Pulse........................................................................................19
7.3.3 Pulse output............................................................................................................19
7.3.3.1 Pulse length .................................................................................................19
7.3.3.2 Pulse interval................................................................................................19
7.3.4 Filter........................................................................................................................19
7.3.5 Reset sum...............................................................................................................19
7.3.6 Old sum..................................................................................................................19
7.3.7 Recall Sum .............................................................................................................19
7.3.8 Security code..........................................................................................................19
7.4 Warning........................................................................................................................20
7.4.1 Mode.......................................................................................................................20
7.4.2 Value ......................................................................................................................20
7.4.3 Hysteresis...............................................................................................................20
7.4.4 Tv delay time ..........................................................................................................20
7.4.5 Tn stopping time (from Rev2.11).............................................................................21
7.4.6 Warning signal........................................................................................................21
7.4.7 Filter(from Rev2.14)................................................................................................21
7.5 Setting..........................................................................................................................21
7.5.1 Language................................................................................................................22
7.5.2 Output.....................................................................................................................22
7.5.3 Filter........................................................................................................................22
7.5.4 Touchtone...............................................................................................................22
7.5.5 Resolution...............................................................................................................22
7.5.6 Zeroing ...................................................................................................................22
7.5.7 SMU (creep suppression) .......................................................................................22
7.5.8 Illumination..............................................................................................................23
7.5.9 Colour change ........................................................................................................23
7.5.10 Brightness.............................................................................................................23
7.5.11 Contrast................................................................................................................23
7.5.12 Read factory settings ............................................................................................23
7.5.13 Code?...................................................................................................................23
7.6 Operation.....................................................................................................................23
8 Interfaces (optional)...........................................................................................................24
8.1 Settings of the serial interface......................................................................................24
8.2 Settings of the USB port...............................................................................................24
8.3 List of commands.........................................................................................................25
9 Technical data...................................................................................................................28

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10 Troubleshooting...............................................................................................................29
11 Dimension drawing..........................................................................................................30
12 Menu tree........................................................................................................................31

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Purpose of instruction manual
This instruction manual describes the features of the P26 and provides guidelines for its use.
Improper use of this instrument or failure to follow these instructions may cause injury or
equipment damage. Every person who uses this device must therefore read the manual and
understand the possible risks. The instruction manual, and in particular the safety precautions
contained therein, must be followed carefully.
Contact the manufacturer if you do not understand any part of this instruction manual.
Handle this manual with care:
It must be readily available throughout the lifecycle of the instrument.
It must be provided to any individuals who assume responsibility for operating the
instrument at a later date.
It must include any supplementary materials provided by the manufacturer.
The manufacturer reserves the right to continue developing this instrument model without
documenting such development in each individual case. The manufacturer will be happy to
determine whether this manual is up-to-date.
Conformity
This device is state of the art. It complies with the legal requirements of EC
directives. This is shown by the CE mark.
© 2012, 2014, 2015, 2017
The manufacturer owns the copyright to this instruction manual. It contains technical data,
instructions and drawings detailing the device’s features and how to use it. It must not be copied
either wholly or in part or made available to third parties.

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Safety precautions
2.1 Appropriate use
The P26 is used to measure pressure, volumetric flow, mass flow and flow rate.
Always observe the operating requirements –particularly the permissible supply voltage –
indicated on the rating plate and in the “Technical data” section of this manual.
The instrument may only be handled as indicated in this manual. Modifications to the
instrument are prohibited. The manufacturer is not liable for damages caused by improper use
or failure to follow these instructions. Violations of this type render all warranty claims null and
void.
2.2 Shipping, assembly, electrical connections and start-up
Do not close the pressure inlets during shipping. Changes in barometric pressure may
damage devices with low measuring ranges.
Assembly and the electrical connections should only be handled by professionals. They should
be given proper training and be authorised by the operator of the facility.
Although the P26 pressure transducer is highly robust, it is nevertheless a precision instrument
and should be handled with care. Avoid mounting the P26 in the direct vicinity of any sources
of heat or radiation. Ideally, the instrument should be mounted vertically on a wall not subject
to vibration.
The instrument may only be operated by appropriately trained individuals who have been
authorized by the operator of the facility.
Do not carry out a function test with compressed or breathable air. This would damage
instruments with low measuring ranges.
The pressure ports may only be connected and disconnected when the device is switched off.
Measurement errors may occur if the instrument is not kept protected from sunlight.
Specific safety precautions are given in individual sections of this manual.

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2.3 Troubleshooting, maintenance, repairs, disposal
The individual responsible for the electrical connections must be notified if the instrument is
damaged or if errors occur that cannot be corrected as indicated in Section 10.
This individual must take the instrument out of service until the error has been corrected and
ensure that it cannot be used unintentionally.
Always unplug the power cord resp. shutdown all supply voltages before opening the
instrument!
This instrument requires no maintenance.
Only the manufacturer may perform repairs that require the housing to be opened.
The electronic components of the instrument contain environmentally hazardous materials and
materials that can be reused. The instrument must therefore be sent to a recycling plant when
you no longer wish to use it. The environment codes of your particular country must be
complied with.
2.4 Symbols
The symbols given below are used throughout this manual to indicate instances when
improper operation could result in the following hazards:
WARNING! This warns you of a potential hazard that could lead to bodily injury up to
and including death if the corresponding instructions are not followed.
WARNING: This warns you of a potential hazard that could lead to significant
property damage if corresponding instructions are not followed.
INFORMATION! This indicates that the corresponding information is important for
operating the instrument properly.

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Instrument description
3.1 Functions
The P26 is controlled by a microprocessor and can
measure pressure and vacuum
measure differential pressure
measure volume flow, mass flow and flow rate
display a measured value
monitor a variety of threshold parameters
-
+
Actual pressure value
Calculation:
volume flow
mass flow
flow rate
µC
Pressure measurement
Valves
pos. pressure
neg. pressure
Display Serial inter-
face
Relay
Keyboard
Analogue output signal
Fig. 1: Basic circuit diagram

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3.2 User interfaces
The following four keys are available:
Menü UP Right Enter
Key
Meaning (Measurement Mode)
Meaning (Menu)
Menu
Start Menu
Go back a menu level
Enter
Start zero-point calibration
Confirm
Up arrow
Max. display
Increases a value or scrolls up
Right
arrow
Min. display
Moves the arrow or scrolls down
In measurement mode, the keys perform the following functions:
The Enter key starts a zero-point calibration
▲- key shows the maximum (to reset: press Enter while the maximum is being displayed)
►- key shows the minimum (to reset: press Enter while the minimum is being displayed)
When the air consumption function is activated, the keys perform the following functions:
The Enter key starts a zero-point calibration
Press the “▲“ key to display the current mass or volume flow.
Press the “►“ key to display the current value for the operating hours meter.

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3.3 Internal connections and buttons
Standard version
Version with external zero-point calibration

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Standard version
Output signal Relay1 Relay2 Power supply
RS232 interface for PC Reset
Version with external zero-point calibration
Output signal Relay1 Relay2 Power supply
External zero-point calibration
RS232 interface for PC Reset

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Output signal:
Port designation
Description
I
current output
GND
earth
U
voltage output
N (optional)
+24 V starts external zero-point
calibration
Relay 1:
Port designation
Description
4 CLOSING CONTACT
active position
5 CENTRE CONTACT
middle position
6 OPENING CONTACT
rest position
Relay 2:
Port designation
Description
7 OPENING CONTACT
rest position
8 CENTRE CONTACT
middle position
9 CLOSING CONTACT
active position
Power supply:
o24V DC
Left contact => Ground
Central contact => +24V DC
o24V AC
Left contact => Ground
Central contact => +24V AC
with transformer
o115V AC
Central contact and right contact
o230V AC
Left contact and right contact
o24 VAC
left contact and right contact
RS232 interface for PC:
RS232 interface for parameter settings
Reset:
Pressing this button restarts the processor.

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3.4 Front view
USB (optional) C a b l e g l a n d s:
Signal Relay Power supply
Pressure ports: + -
RS-232:
Port designation
PIN
Description
RXD
3
receive
TXD
2
send
GND
5
earth
USB:
Port designation
PIN
Description
Power
1
power supply via USB port of
the PC
D- bidirectional
2
USB data, negative polarity
D+ bidirectional
3
USB data, positive polarity
ID
4
not used
Ground
5
GND = USB signal earth
Case Ground
shield
shielding via PC case
INFORMATION!
The greatest possible accuracy is achieved at room temperature (20°C).

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Zero-point calibration cycle
External influences such as temperature, position or ambient pressure can shift the instrument’s
zero-point, i.e., the value displayed when the pressure ports are open. During calibration, the
instrument automatically calculates this shift and takes it into account during the zero-point
calibration. The zero-point calibration takes place in two steps, which are shown in the top line
of the display (optional).
“0” Measuring signal of the zero-point is being determined.
“P” Pressure is being reconfigured
The interval between two zero-point calibrations can be adjusted in the Settings menu.
Zero-point calibration can also be started with the Enter key if the device is in Measurement
mode.
The P26 does not respond to keys being pressed during calibration.
4.1 External zero-point calibration (optional)
External zero-point calibration is also available (optional). In this version, there is an additional
contact on the output connector. To initiate a zero-point calibration, this connection must be
connected briefly with +24 V.
INFORMATION!
If a zero-point calibration is initiated via the serial interface or the external zero-point
calibration input, this will still be carried out. In this case, it doesn’t matter if the zero-point
calibration is deactivated or the P26 is in the menu.
Overpressure protection
The P26 has an internal overpressure safeguard that protects the precision pressure
measurement capsule from damage. (Overload range: 200 x [max. 600 kPa])
Display (optional)
The measured values and the menu are shown on the display. The top line is the information
line. This line displays the type of measured value or the status of a zero-point calibration. The
measured value is displayed in the middle line. If the permitted measuring range is exceeded or
not reached, the figures are replaced by '-' characters. The bottom line displays the unit, with the
first two digits showing the status of the two relays.

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Menu (optional)
If the P26 includes a display, you can use the menu to adjust various settings. Press the Menu
key to bring up the menu.
In Menu mode, the parent menu item always appears in the top display line. The middle line
always shows the current sub-menu item or value to be changed. The bottom line displays units
or other help texts.
Start the Menu mode by pressing the "Menu" key. It can be protected with a four-character
password. At the main menu level, “Menu” is displayed in the top line and “Display” in the
middle line. Select your desired sub-menu by pressing the “▲” and “►” keys. Press “Enter” to
go to a sub-menu or enter a value. Press the “Menu” key to go to the next menu level or to stop
entering values.
7.1 Display
The display unit can be selected with this menu item. Press the “▲” and “►” keys to select the
unit you want and press “Enter” to confirm. The type of display (pressure, flow rate etc.) is
selected automatically.
When the air consumption function is activated, the selection of units that can
be displayed is limited to the following: m³/s, m³/h, ft³/h, kg/s, kg/min or kg/h.
7.2 Scale
The scaling function is not available when the air consumption function is
activated. Entering the scaling values defines the density of the medium.
Changing these values when the air consumption function is activated will result
in the calculation of incorrect totals.
The P26 is usually supplied with standard measuring ranges. You can use the scale to adjust
the measuring range for your own use. The output voltage or currents are then copied to this
scaled range. The scaled range should always be more than 0.1 times of that of the P26’s
measuring range, because otherwise the resolution of the outputs and the accuracy will be
poorer.
With this menu item, there are 4 sub-menu items:
Pressure
Volume flow
Mass flow
Flow rate

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Pressure
This is an important menu item. It is used to specify the pressure range, which indicates the
output value. This pressure range forms the basis for many other settings such as the limits for
the relays (warnings) and factors for the flow display.
There are two default settings for the pressure scale:
Top = Pressure at which the output has its maximum value (e.g. 5V, 10V or 20 mA)
Bottom –Pressure at which the output has its minimum value (e.g. -5V, 0V, 0mA or
4mA)
Because the values can be freely assigned, settings such as 0V at 0Pa or 10V at -250Pa are
also possible.
7.2.1.1 Top
With this menu item, you can set the pressure at which the output will achieve its maximum
value. Any value within the measuring range can be selected. It can also be less than the
lower scale value.
7.2.1.2 Bottom
With this menu item, you can set the pressure at which the output will achieve its minimum
value. Any value within the P26’s measuring range can be selected.
7.2.1.3 Units
Use this menu item to select the pressure unit. The following pressure units can be selected:
Pa
hPa
kPa
mbar
mmH2O
mmHg
Psi
inH2O
inHg
Volume flow
This menu item is used to adjust the volume flow display values.
The following sub-menu items are available:
Value
Units

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7.2.2.1 Value
This is used to set the volume flow value displayed at the maximum scaled pressure. 0 is
always used as the lower scale value on the volumetric flow display (root-extracted measured
value). The maximum pressure is the larger of the two scale values, which is used as a basic
calculation.
7.2.2.2 Units
You can use this menu item to select the scaling unit of the volume flow value. This unit don’t
have to be identical to the selected display unit. The following volume flow units can be
selected: m³/s, m³/h, ft³/h.
Mass flow
This menu item is used to adjust the mass flow display values.
The following sub-menu items are available:
Value
Units
7.2.3.1 Value
This is used to set the mass flow value displayed at the maximum scaled pressure. 0 is always
used as the lower scale value on the mass flow display (root-extracted measured value). The
maximum pressure is the larger of the two scale values, which is used as a basic calculation.
7.2.3.2 Units
You can use this menu item to select the scaling mass flow unit. This unit don’t have to be
identical to the selected display unit. The following mass flow units can be selected: kg/s,
kg/min, kg/h
Flow rate
This menu item is used to adjust the flow rate display values.
The following sub-menu items are available:
Value
Units
7.2.4.1 Value
This is used to set the flow rate value displayed at the maximum scaled pressure. 0 is always
used as the lower scale value on the flow rate display (root-extracted measured value). The
maximum pressure is the larger of the two scale values, which is used as a basic calculation.
7.2.4.2 Units
Use this menu item to select the scaling flow rate unit. This unit don’t have to be identical to
the selected display unit. The following flow rate units can be selected: m/s, mph, f/s, f/min,
km/h

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7.3 Air consumption function (option available from firmware version 3.0)
The air consumption function is only available if you have selected one of the following
units as the display unit:
m³/s, m³/h, ft³/h, kg/s, kg/min or kg/h.
This function records the consumed volume or mass of the medium being measured. The
settings are protected by a separate code. You can change the parameters after entering the
correct code. The code remains active until you leave the menu. After switching to the display
mode, you must re-enter the code if you wish to change the parameters.
Mode
A number of modes are available for recording the volume(s):
7.3.1.1 Off
Recording of consumption values is deactivated. The scaling function is available.
7.3.1.2 Σ(ΔP >0)
Recording of the quantity consumed only for pressures > 0. When creep suppression is
activated, only pressures greater than the amount of creep will be recorded.
7.3.1.3 Σ(ΔP)
Recording of the consumption values also takes negative differential pressures into account.
The consumption or mass values calculated from the negative pressures are deducted from
the total.
7.3.1.4 Σ(abs ΔP)
In this mode, the sign (+/-) of the differential pressures is not taken into account. In both cases,
the consumption or mass value calculated is added to the total.

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Mass/Pulse or Vol./Pulse
The recorded consumption values are signalled to the connected control module by a relay.
Every pulse corresponds to a defined volume or a definable mass. This menu item can be
used to set this volume or mass. The parameter displayed depends on the display units
selected. Adjusting the scaling feature adjusts the associated volume or mass value. This
enables you to switch between displaying mass and volume readings even while the unit is
operating. Values are adjustable between 0.1 and 10000 m³ or kg.
The pulse output can generate a pulse rate of max. 5 pulses/s. Adjust
volume/pulse or mass/pulse so that this pulse rate is not exceeded even at the
max. flow rate. If the pulse rate is exceeded, the output will continue to pulse
even when the section is not sending a signal as it attempts to transmit all the
accumulated pulses. Longer periods of activation or inactivity also reduce this
pulse rate.
Pulse output
This menu item is used to adjust the pulse length and the min. break for the volume or mass
pulses.
7.3.3.1 Pulse length
This parameter is used to defined the duration of the relay pulse. Values are adjustable
between 20 and 1999ms.
7.3.3.2 Pulse interval
This parameter is used to define the min. break after a relay pulse. Values are adjustable
between 50 and 1999ms.
Filter
Either the filtered or unfiltered value can be used to record the consumption values. Use this
setting to select either the filtered or unfiltered value.
Reset sum
This function is used to reset the sum for the consumption function. The last value is saved as
backup. (Yes --> Sum = 0, No --> Sum is retained)
Old sum
This menu item is used to display the consumption values sum from before the last reset.
Recall Sum
This function can be used to restore the sum for the consumption function from before the last
sum reset. (Yes --> Recall, No -- Current value is retained.)
Security code
This function can be use to set the code for accessing the menu. You should set a security
code when the air consumption function is activated in order to prevent the device from being
manipulated. When the security code is > 0000, it is only possible to access the menu after
entering this security code.

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7.4 Warning
Use this menu item to influence the behaviour of the relays. The first menu item that appears
here is Select Relay. The settings for this relay should then be changed. Use the “▲” and “►”
keys to select the number of the relay and press Enter to move to that relay's menu.
The following sub-menu items are available:
Mode
Value
Hysteresis
Tv
Tn
Warning signal
Filter
Mode
During normal operation, the relay outputs are used to signal when values rise above or fall
below definable pressure limits. This parameter can be used to influence the behaviour of the
relays.
The following settings are available:
Off Relay not active
Increasing Relay triggered when the pressure rises above the warning
pressure threshold (dependent on air pressure)
Decreasing Relay triggered when the pressure rises above the warning
pressure threshold (dependent on air pressure)
Air consumption Relay is used as a pulse output for the air consumption function
if this is activated, otherwise the relay is deactivated
In "air consumption" mode, the other relay parameters are not used and
therefore not displayed in the menu.
Value
This item adjusts the pressure value at which the particular relay should switch. The pressure
range defined by the scale can be used as the setting range. Select the pressure unit set for
the display as the unit.
Hysteresis
This item can be used to select the hysteresis for the particular relay. If the volume flow, mass
flow or flow rate (root-extracted display) is displayed, the pressure unit used will be the unit
that was active at the time when the root-extracted display was activated. The hysteresis is
always positive and can be set between 0% and 120% of nominal pressure value.
Tv delay time
The entry value of the relays is derived from the unfiltered pressure value. With this parameter,
you can now specify how long the pressure value can be exceeded or not met until the relay
switches. The adjustment is done in ms.