Meriam 2110P Instruction Manual

File No. 2110P:440-3

2110P SMART PRESSURE GAUGE

OPERATING INSTRUCTIONS

Meriam Instrument’s 2110P Smart
Pressure Gauge is a microprocessor-based
pressure sensing device. The various
ranges available provide measurement of
pressure, differential pressure, vacuum and
absolute pressure. Three configurations
are available: Battery, SetPoint, and
Current Loop models.

All models are programmable through the
front keypad, to allow configuration of the
gauge. The user’s program information is
stored in non-volatile memory, and is
retained when the power to the gauge is
removed. SetPoint and Current Loop
models can also be configured through the
RS-232 serial communication connection.

The Battery model is powered by its internal lithium batteries only. This model does not provide
any outputs or RS-232 communications.

SetPoint and Current Loop models have outputs that can be used for control or
indicating/recording functions. Both models also have RS-232 communications capability. In
addition to configuring the gauge, the RS-232 port can be used to monitor and log the measured
pressure data and output status. It can also be used as part of a control system with digital
capabilities.

The SetPoint model provides two SPDT relay outputs with adjustable deadband. This
configuration provides normally open or normally closed contact operation for fail-safety.
Switching SetPoint can be set from –20% to +120% of the full scale pressure range. The
SetPoint model is powered by 120/240 VAC, or 24VDC.

The Current Loop model provides a 4 to 20 mA output, and is intended to be used as a pressure
transmitter on a three or four wire loop. Zero and span are set through user-programmable
registers, from –20% to +120% of the full scale pressure range. The output is capable of normal
and reverse action. The Current Loop model is powered by 24VDC only.

10920 Madison Avenue • Cleveland, Ohio 44102 • [phone] • Fax: [phone]

www.meriam.com

Table of Contents

PRESSURE DISPLAY................................................................................................................... 1

KEYPAD FUNCTIONS:................................................................................................................ 2

PROGRAMMABLE REGISTER OVERVIEW ............................................................................ 3

ENGINEERING UNITS................................................................................................................. 4

ZERO REFERENCE ...................................................................................................................... 5

P0 – LOCKOUT CODE ................................................................................................................. 6

P1 – TIMEOUT VALUE................................................................................................................ 7

P2 – DAMP RATE ......................................................................................................................... 8

P3 – DENSITY OF WATER REFERENCE TEMPERATURE.................................................... 9

P4 – USER SCALE ...................................................................................................................... 10

P5 – SETPOINT OPTIONS.......................................................................................................... 12

P6 and P7 – SETPOINT (SET1 and SET2)................................................................................. 13

P8 – DEADBAND........................................................................................................................ 15

LOCKOUT CODE PROMPT....................................................................................................... 16

SERIAL PORT SERVICE............................................................................................................ 17

ERROR CODES ........................................................................................................................... 19

INSTALLATION AND WIRING................................................................................................ 20

PRODUCT SPECIFICATIONS ................................................................................................... 22

PROGRAMMABLE REGISTER QUICK REFERENCE ........................................................... 22

i

PRESSURE DISPLAY

Indicators

During normal operation, the gauge displays the pressure value in large numerals, and the bottom of the
display shows the current Engineering Unit. The top of the display will show PRGM when the gauge is in

Program Mode (flashing when “view only”). For SetPoint models, the top of the display will show
SET1/SET2 to indicate activated outputs (or corresponding register opened in Program Mode). For

Current Loop models, the top of the display will show 4-20mA when the output is enabled (or
corresponding register opened in Program Mode). Finally, an ABS indicator illuminates when an
Absolute Isolated sensor is used.

Performance

The 2110P Smart Gauge retrieves analog data from its pressure sensor, and performs an analog-to-digital
(A/D) conversion for microprocessor-based data handling. The rate of A/D conversion will typically be
between 10 to 14 conversions per second, depending on the various operating conditions.

To make the display easier to read, only every fourth sample is updated on the display. (This results in a
display update rate of about 3 updates per second.) The internal calculations, outputs, and serial interface
are updated at the full conversion rate.

Resolution

The display is limited to 4½ digits, and the resolution of the data (decimal point positioning) is defined by
the range and sampling process. The resultant full scale display and data resolution is summarized in the
table below. If a specific value will not fit on the 4½ digit display, however, the auto-range feature will
decrease the resolution to allow the value to fit the display (for example, increasing past 199.99 becomes

200.0). The auto-range feature restores the decimal resolution with a built-in deadband of 5 display counts
(for example, 200.0 must drop to 199.95 before the two-digit decimal resolution is restored).

Note that the full scale display indication during power-up will not necessarily have the same decimal
resolution found during actual pressure monitoring.

Full Scale and Resolution Summary

Note: Add 20% for Max. Capability

Sensor

(20oC)

→

inH2O

20.00

(1)

20.00

inH2O

200.00

(1)

200.00

(1)

inH20

psi

kg/cm2

kPa

mbar

bar

cmH20

inHg

mmHg

Notes:

0.7212 7.212 72.12

0.0571 0.5071 5.071 1.4061 14.061 140.61 1.2230 2.719

4.973 49.73 497.3

(1)

49.728

(1)

497.28

(1)

4.973 0.4973 4.973 1.3789 13.789 137.89 1.117 2.666

(1)

50.800

(1)

508.00

(1)

1.4685 14.685 146.85

(1)

37.299

(1)

372.99

(1)

(1) Auto-range will reduce resolution of these values by one decimal position when

the ½ digit exceeds “1”.

inH2O

2000.0

2000.0

4972.8

5080.0

3729.9

20.000

(1)

554.60

(1)

20.000

(1)

137.895

(1)

1378.95

(1)

1408.67

(1)

40.721

(1)

1034.31

PSI

200.00

(1)

5546.0

(1)

200.00

(1)

1378.95

(1)

13789.5

(1)

14086.7

(1)

407.21

(1)

10343.1

PSI

PSI

2000.0

(2)

19999

(1)

2000.0

(1)

13789.5 119.90

(2)

19999

(2)

19999

(1)

4072.07 35.46 78.74

(2)

19999

mmHg

900.0

(1)

482.6 1072.4

17.364 38.67

(1)

(1)

1199.0

(1)

1225.80

(1)

900.00

(1)

(1)

(1)

mmHg

2000.0

266.64

2666.4

2723.9

2000.0

(2) This value will not fit on the display and will result in an error code instead of a

normal pressure indication (see page 19).

1

KEYPAD FUNCTIONS:

/

The keys on the front panel perform multiple functions. Their function differs depending on whether the gauge is in
Measure Mode or Program Mode.

• Measure Mode is the normal operating mode for measuring and displaying pressure. This mode is always

default after power-up or reset.

• Program Mode is used to configure the various options of the gauge. This mode is denoted by a PRGM

indicator on the display.

ON/OFF /
Backspace Key

Measure Mode

Program Mode

ENG UNITS/Up
Arrow Key

ON

• Battery models: Toggles the gauge ON and OFF.

• SetPoint and Current Loop models: “Resets” the gauge.

Backspace function:

From Program Mode, this key will exit to Measure Mode.

When editing a register, this key is used to abort a programming operation and exit the
register without making any changes.

When editing a multi-digit value, each key press will backup one digit, until finally
exiting the register.

ENG

UNITS

Document Symbol: (Backspace←)

OFF

Sequence of power-up or reset

1. Display test is performed (all segments of the LCD display are turned on).

2. Firmware revision is displayed.

3. Full scale range of sensor is displayed in the last Engineering Unit used.

4. All prior register values are restored and activated.

5. Measure Mode displays pressure in the last Engineering Unit used.

Document Symbol: (Up↑)

Measure Mode

Program Mode

(and EU Selection)

Backlight/Down
Arrow Key

Measure Mode

Program Mode

(and EU Selection)

Allows the Engineering Units to be changed (see page 4). During Engineering Unit
selection, the current unit indicator remains solid, and the “new” unit indicator is flashed.
Scrolling through the available units is done by pressing the Up↑ or Down↓ keys. The
flashing unit is selected using the PRGM/Enter→ key, or the process may be aborted by
using the Backspace← key.

Scroll up function. Scrolls up through the available programmable registers. Once a
register is opened, this key allows editing by scrolling up through the values in the
register.

Document Symbol: (Down↓)

Toggles the display Backlight on and off. Note that the default Backlight status for the
Battery model is OFF to conserve battery life. The other models will retain the prior
Backlight status as default.

Scroll down function. Scrolls down through the available programmable registers. Once
a register is opened, this key allows editing by scrolling down through the values in the
register.

2

KEYPAD FUNCTIONS

(cont’d)

PRGM/Enter Key

Measure Mode

(and EU Selection)

Program Mode

Re-ZERO Key

Measure Mode

Program Mode

(and EU Selection)

PRGM

Selects Program Mode, which allows access to the programmable registers. This key
is also used to accept a new Engineering Unit selection.

Opens the selected programmable register for editing.

When the desired value is displayed, pressing the PRGM/Enter→ key accepts and
stores the value, and closes the register.

When editing a multi-digit value, each key press will accept the current digit and proceed
to the next, until finally accepting the complete value and closing the register.

ENG

UNITS

In Measure Mode, pressing the Up↑ and Down↓ keys at the same time resets the zero
reference of the gauge (see page 5).

In Program Mode, for convenience, this function will reset the current value to default.

Document Symbol: (PRGM/Enter→)

Document Symbol: (Up↑ and Down↓)

+

For example, in Program Mode (but before opening a register), this function
will reset the register scroll to P0.

After opening a register for editing, this function will reset the register’s data
value to default (typically 0).

Similarly, when selecting a new Engineering Unit, this function will reset the
selection to the first unit (InH

Note that even when using this “reset” function, the PRGM/Enter→ key must be
pressed to accept the new value (this allows for further editing after reset of the value).

2

O).

PROGRAMMABLE REGISTER OVERVIEW

All 2110P Smart Pressure Gauges have programmable registers that allow the gauge to be configured to fit the
pressure measurement application. Programmable registers are numbered P0 through P8. Each register controls a
specific aspect of the gauge’s performance.

Beginning on page 6 is a description of all programmable registers, and instructions for their use. Each register is
found on all 2110P models, and performs the same function described for all models, except as noted otherwise.

3

ENGINEERING UNITS

The following Engineering Units are available on the 2110P:

1. InH

O – Inches of Water Column (reference selectable: 20°C, 4°C, 60°F; see P3 on page 9)

2

2. PSI – Pounds per Square Inch

3. Kg/cm

2

– Kilograms per Centimeter squared

4. kPa – KiloPascals

5. mBar – milliBar

6. Bar – Bar

7.

cmH2O – Centimeters of Water Column
inHg – Inches of Mercury Column (reference 0°C)

8.

9.

mmHg – milliMeters of Mercury Column (reference 0°C)

10.

User Units – User Defined Units (refer to P4, User Scale on page 10)

(reference selectable: 20°C, 4°C, 60°F)

STEP BY STEP: CHANGING ENGINEERING UNITS

Step Action Display

1

2

3

4

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the ENG UNITS (Up↑) key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired Engineering Unit.

The Zero function (Up↑
first unit and allow selection to continue.

Press the PRGM/Enter→ key when the desired
unit is flashing.

Down↓) will reset the scroll to the

and

Current Engineering Unit1 indicator flashes.

The current Engineering Unit indicator remains
solid since it is active, and the unit to be selected
flashes as the list is scrolled.

The display switches to the new Engineering Unit
and returns to Measure Mode.

2

Notes

1. When scrolling through Engineering Units, User Units are denoted by all units flashing.

2. In Measure Mode, User Units are denoted by no Engineering Unit indicators shown on the bottom

of the display.

3. Changing the Engineering Unit will automatically update the setpoint registers as appropriate (refer

to the Automatic Update section on page 13 for further explanation).

4. At any time, the Backspace← key will abort the process and return to Measure Mode.

5. If there is no keypad activity for approximately 1 minute, the operation is aborted and the gauge

returns to Measure Mode unchanged.

4

ZERO REFERENCE

p

y

Zeroing the gauge consists of accepting the current pressure value as the zero pressure reference. To set the zero
reference pressure, all pressure sources should be disconnected from the gauge, and its temperature should be stable.

The pressure reading of the gauge is linearly offset from the zero reference value. Absolute-Isolated pressure
sensors are theoretically zero-referenced to absolute zero pressure (perfect vacuum), and cannot be re-zeroed
without a vacuum source.

AFFECT ON OUTPUTS

The SetPoint and Current Loop outputs are calculated based on the displayed pressure. Since re-zeroing
the gauge may change the displayed pressure, the outputs may change accordingly. For safety purposes, if
the outputs are active (defined by register P5; see page 12), an extra step is required to warn the operator
and confirm the desired action. For clarity, both scenarios are described below, step-by-step.

FACTORY ZERO

The “Factory Zero” can be restored through the serial port service only (SetPoint and Current Loop models
only). This is the value set during calibration of the sensor, and is typically 0.0.

RANGE CHECK

The 2110P can be zeroed only when the applied pressure is within ±5% of full scale. If the applied
pressure is greater than 5% of full scale, an error code will be displayed when zeroing is attempted.

STEP BY STEP: RE-ZEROING THE GAUGE (Disabled Outputs, P5=0)

Step Action Display

1

2

Gauge should be in normal Measure Mode, and the
applied pressure is ready for zeroing (typically
vented, or vacuumed for absolute sensors).

Press the Up↑ and Down↓ keys simultaneously.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Normal pressure display, near 0.0.

The display will flash “0000” several times while
the new zero is taken, and then return to Measure

Mode with the new zero activated.

WHEN OUTPUTS ARE ACTIVE (P5>0) ...

1

2

3

Gauge should be in normal Measure Mode, and the
applied pressure is ready for zeroing (typically
vented, or vacuumed for absolute sensors).

Press the Up↑ and Down↓ keys simultaneously.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press PRGM/Enter→ before the countdown

1

expires

. This acknowledges the warning.

Normal pressure display, near 0.0.

The display will begin countdown from
“0005” to “0000”.

The display will again countdown from
“0005” to “0000”.

SetPoint and Current
Loo

models onl

4

Notes

Press ZERO again (Up↑ and Down↓) before the
countdown expires

1. During steps 2 or 3, if the countdown expires, the gauge will return to Measure Mode unchanged.

2. During steps 2 or 3, the Backspace← key will abort the process and return to Measure Mode.

1

. This confirms the zero action.

The display will flash “0000” several times while
the new zero is taken.

5

P0 – LOCKOUT CODE

This feature provides security in the 2110P. It is designed to prevent unauthorized personnel from tampering with or
inadvertently changing the configuration of the gauge. The lockout is controlled by a 2-digit setting in the P0
register. Once a lockout code is entered, the gauge will prompt for the lockout code before allowing any changes
(similar to a “password”). Changes include Engineering Unit selection, re-zeroing, or entering Program Mode.

Following an operator action, if the correct code (password) is not entered when prompted, an error message is
briefly displayed. If the operator action was changing Engineering Units or re-zero the gauge, the gauge will simply
return to normal Measure Mode operation, without accepting any change. If the operator action was entering
Program Mode, the gauge will enter a “view-only” status (see page 16), denoted by the PRGM indicator flashing.

In Program Mode (and during lockout code prompting), the register value is shown as “L xx” to assist in
identifying the register. The “L ” indicates “Lockout”, and “xx” will consist of the current value.

All Models

QUICK REFERENCE: P0, LOCKOUT CODE

Px

Name Description Value Range Notes

P0 Lockout Code Lockout for security. 00 to 99 00 = Disabled.

STEP BY STEP: P0, LOCKOUT CODE

Step Action Display

1

2

3

4

5

6

7

Notes

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press PRGM/Enter→ again, to open the register.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired numeric value for the flashing digit.

The Zero function (Up↑
register to 00 and allow editing to continue.

Press the PRGM/Enter→ key to accept the digit.

Repeat steps 4 and 5 for the second digit. The complete 2-digit value will be accepted, and

Press the Backspace← key to activate the lockout
and return to Measure Mode.

1. After step 2, the Backspace← key will abort the process and return to Measure Mode.

2. After steps 3 or 4, the Backspace← key will abort the current digit and close the register (since it is

the first digit).

3. After step 5, the Backspace← key will abort the current digit and backup to the first digit. Another
Backspace← will abort the process and close the register.

4. After step 6, the PRGM/Enter→ key will again open the register for edit.

5. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

Down↓) will reset the entire

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

The display will show “L xy” with the first digit
flashing for edit (indicating Lockout Code xy).

“L _x”, where “_” is the digit being edited
(flashing).

The next digit begins flashing for edit.

the register is closed (display shows P0 for
selection).

Normal Pressure Display.

6

P1 – TIMEOUT VALUE

This register sets the length of time (in minutes) for automatic shutoff. The Battery model will automatically shutoff
if there is no keypad activity for this length of time. This feature can be disabled by selecting 0 in the register,
which allows the gauge to remain on indefinitely, or until the ON/OFF key is pressed (battery life may be reduced).
During programming, the choices found in the register correspond to the actual timeout values, in minutes.

Battery Model Only

QUICK REFERENCE: P1, TIMEOUT

Px

Name Description Value Range Notes

P1 Timeout Automatic shutoff in minutes of

keypad inactivity.

0 (disabled),
1, 2, 5, 10, 15, 25

STEP BY STEP: P1, TIMEOUT

Step Action Display

1

2

3

4

5

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Press PRGM/Enter→ to open the register.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register value.

The Zero function (Up↑
default and allow editing to continue.

Down↓) will reset the scroll to P0

and

Down↓) will reset the scroll to

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P1”.

The display shows the current value.

All available choices are scrolled.

(Choices indicate actual Timeout in seconds.)

Battery model
only.

6

7

Notes

Press the PRGM/Enter→ key to accept the desired
value.

Press the Backspace← key to activate the register
setting and return to Measure Mode.

1. After steps 2 and 3, the Backspace← key will abort the process and return to Measure Mode.

2. After steps 4 and 5, the Backspace← key will abort the edit and close the register.

3. After step 6, the PRGM/Enter→ key will again open the register for edit.

4. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

The value is accepted, and the register is closed.
Display shows “P1”.

Normal Pressure Display.

7

P2 – DAMP RATE

The 2110P has a selectable damp rate, which is used to stabilize the display for applications with a pulsating
pressure source. The damp rate setting is roughly the length of time it will take for the gauge to ramp from one
stable pressure to another. The ramping is exponential, changing at a slower rate as the final value is approached.

The “time constant” of the exponential equation is roughly one-fifth of the damp rate setting. This means that the
damped value will be roughly 63% of final value after a time equal to one-fifth of the register setting. The value
will be roughly 86% of final value after a time equal to two-fifths of the register setting.

The damping function only affects the displayed value (LCD display and RS232 data); it does not affect the action
of the SPDT relays, the 4 to 20 mA outputs, or the response to over-pressure (“OP” indication).

All Models

QUICK REFERENCE: P2, DAMP RATE

Px

Name Description Value Range Notes

P2 Damp Rate Exponential damping time in

seconds.

0.1, 0.2, 0.5, 1, 2,
5, 10, 15, 25, 50

STEP BY STEP: P2, DAMP RATE

Step Action Display

1

2

3

4

5

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Press PRGM/Enter→ to open the register.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register value.

The Zero function (Up↑
default and allow editing to continue.

Down↓) will reset the scroll to P0

and

Down↓) will reset the scroll to

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P2”.

The display shows the current value.

All available choices are scrolled.

(Choices indicate actual damp rate in seconds.)

0.1 = No
Damping.

6

7

Notes

Press the PRGM/Enter→ key to accept the desired
value.

Press the Backspace← key to activate the register
setting and return to Measure Mode.

1. After steps 2 and 3, the Backspace← key will abort the process and return to Measure Mode.

2. After steps 4 and 5, the Backspace← key will abort the edit and close the register.

3. After step 6, the PRGM/Enter→ key will again open the register for edit.

4. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

The value is accepted, and the register is closed.
Display shows “P2”.

Normal Pressure Display.

8

P3 – DENSITY OF WATER REFERENCE TEMPERATURE

The 2110P supports pressure units of inches of water column and centimeters of water column, at three different
water temperature references: 20°C, 4°F and 60°F. The base reference temperature is 20°C on all gauges. This
register is used to change to one of the other standards. During programming, the corresponding choices found in
the register are “20”, “4”, and “60” respectively (the temperature unit cannot be shown due to display limitations).

All Models

QUICK REFERENCE: P3, DENSITY OF WATER REFERENCE TEMP

Px

Name Description Value Range Notes

P3 Density of Water

Reference
Temperature

Sets reference temperature for
water density when gauge is set
for water column units.

STEP BY STEP: P3, DENSITY OF WATER REFERENCE TEMP

Step Action Display

1

2

3

4

5

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Press PRGM/Enter→ to open the register.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register value.

The Zero function (Up↑
default and allow editing to continue.

Down↓) will reset the scroll to P0

and

Down↓) will reset the scroll to

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P3”.

The display shows the current value.

All available choices are scrolled.
“20” = 20 Deg. C
“4” = 4 Deg. C
“60” = 60 Deg. F

20°C
4°C
60°F

6

7

Notes

Press the PRGM/Enter→ key to accept the desired
value.

Press the Backspace← key to activate the register
setting and return to Measure Mode.

1. After steps 2 and 3, the Backspace← key will abort the process and return to Measure Mode.

2. After steps 4 and 5, the Backspace← key will abort the edit and close the register.

3. After step 6, the PRGM/Enter→ key will again open the register for edit.

4. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

The value is accepted, and the register is closed.
Display shows “P3”.

Normal Pressure Display.

9

P4 – USER SCALE

The user scale feature is provided in addition to the standard Engineering Unit choices, to allow the display of
measured pressure in any Engineering Unit. The full scale value of the sensor is linearly re-scaled to the value
entered in this register (when User Units are selected as the Engineering Unit; see page 4). This is particularly
useful for displaying linear tank levels in volumetric or mass units.

For example, a 20 PSIG gauge is programmed to read out in feet of water head by entering 46.22 in the P4 register.
This sets the gauge to read from 0 to 46.22 feet of water, when User Units are selected as the Engineering Units
(46.22 feet of water at 20°C is equal to 20 PSIG).

User Engineering Units are selected when ALL Engineering Units are flashing during the Engineering Unit selection
process. Once selected, in Measure Mode, all Engineering Units are cleared from the display to denote user-units.

All Models

QUICK REFERENCE: P4, USER SCALE

Px

Name Description Value Range Notes

P4 User Units

Full Scale

Enables gauge to display units
other than factory defined

0 to 9,999 (Keypad)

0 to 19,999 (Serial)

Engineering Units.

STEP BY STEP: P4, USER SCALE

Step Action Display

1

2

3

4

5

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Press PRGM/Enter→ to open the register.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired numeric value for the flashing digit.

The Zero function (Up↑
register to 0000 and allow editing to continue. The decimal
point will not be affected, and same digit will be flashing.

Down↓) will reset the scroll to P0

and

Down↓) will reset the entire

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P4”.

The display will show the current value, with the
first digit flashing for edit.

“_xxx”, where “_” is the digit being edited
(flashing).

User defined
value.

6

7

Press the PRGM/Enter→ key to accept the digit.

Repeat steps 5 and 6 for the all remaining digits.

The Backspace← key will backup one digit at a time, or abort
and close the register if the first digit is flashing.

The PRGM/Enter→ key will accept one digit at a time, moving
to the next, or accept the complete value and close the register
after the decimal point edit.

The next digit begins flashing for edit.

After Enter→ when the last digit is flashing, the
decimal point flashes for edit.

Please read carefully note 4 below.

10

STEP BY STEP: P4, USER SCALE (cont’d)

Step Action Display

8

9

10

Notes

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired decimal point position.

If the Zero function (Up↑
point editing, it will still reset the register’s value to 0000, and
not affect the decimal point position.

Press the PRGM/Enter→ key to accept the
complete value.

Press the Backspace← key to activate the register
setting and return to Measure Mode.

1. Preceding/Trailing zeroes are determined by where the user places the decimal point. When opening
a register, the value is always shown padded with trailing zeroes.

2. Only 4 digits are available for editing (the ½ digit is not provided), plus the decimal point and
negative sign (negative is not applicable to register P4). This limits keypad value entries to ±9,999,
and also limits the available decimal point resolution (depending on the magnitude of the value). The
serial interface provides much more flexibility.

3. After steps 2 and 3, the Backspace← key will abort the process and return to Measure Mode.

4. The display does not have a physical decimal point that can be illuminated in the least significant
position (to the right of all digits on the display). Thus, if the decimal point is in that particular
position, there will be no decimal point blinking (which may be confusing). When scrolling through
the decimal point selection, it is important to take note that none blinking is a viable setting, and will
be seen in the scrolling sequence.

Down↓) is used during decimal

and

Decimal point moves accordingly.

Please read carefully note 4 below.

The value is accepted, and the register is closed.
Display shows “P4”.

Normal Pressure Display.

5. After step 9, the PRGM/Enter→ key will again open the register for edit.

6. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

11

P5 – SETPOINT OPTIONS

This register defines the output action for SetPoint and Current Loop models. Note that if an output is disabled by
this register, the setpoint value in its corresponding register (P6, P7) has no impact. Also note that a setpoint value
(P6, P7) may be 0.0, which is a viable output setting; thus, in order to disable control action, register P5 should be
used to define the desired action.

In Measure Mode, the indicators “SET1” and/or “SET2” will illuminate when the corresponding relay is energized.
The “4-20mA” indicator will illuminate when the Current Loop output is enabled. In Program Mode, the
indicators “SET1”, “SET2”, and “4-20mA” will illuminate as appropriate to assist when scrolling through the
register’s choices. Note that if P5 is set for active, the outputs will continue to update even in Program Mode,

according to the currently programmed values.

SetPoint & Current Loop Models Only

QUICK REFERENCE: P5, SETPOINT OPTIONS

Px

Name Description Value Range Notes

P5 SetPoint

Options

SetPoint model:

Defines which relay outputs are active.

Current Loop model:

Defines status of the 4-20 mA output.

0 = Disabled.
1 = SET1 only.
2 = SET2 only.
3 = Both enabled.

0 = 4-20 disabled
1 = 4-20 enabled

STEP BY STEP: P5, SETPOINT OPTIONS

Step Action Display

1

2

3

4

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Press PRGM/Enter→ to open the register.

Down↓) will reset the scroll to P0

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P5”.

The display shows the current value.

Not found on
Battery model.

5

6

7

Notes

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register value.

The Zero function (Up↑
default and allow editing to continue.

Press the PRGM/Enter→ key to accept the value.

Press the Backspace← key to activate the register
setting and return to Measure Mode.

1. After steps 2 and 3, the Backspace← key will abort the process and return to Measure Mode.

2. After steps 4 and 5, the Backspace← key will abort the edit and close the register.

3. After step 6, the PRGM/Enter→ key will again open the register for edit.

4. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

Down↓) will reset the scroll to

and

All available choices are scrolled.

The value is accepted, and the register is closed.
Display shows “P5”.

Normal Pressure Display.

12

P6 and P7 – SETPOINT (SET1 and SET2)

SetPoint Model

These registers define the pressure points at which the SPDT relays will energize. The relay will energize
when the pressure exceeds its corresponding value, and de-energize when the pressure drops below the
value (minus deadband; see page 15). P6 defines the SET1 relay, and P7 defines the SET2 relay. P6 and
P7 settings are completely independent of each other; either may be greater, less than, or equal to the other.

Current Loop Model

These registers define the 4 to 20 mA output value. P6 (SET1) sets the 4.00 mA output and P7 (SET2) sets
the 20.00 mA output. (Thus, the output “zero” is defined by SET1, and the “span” is defined by SET2 –
SET1.) When the pressure is at the P6 value, the output will be 4.00 mA; when the pressure is at the P7
value, the output will be 20.00 mA. Other pressures provide an output that is linearly scaled between the
two values. For values beyond the defined range, however, the output is limited from 4.00 to 20.38 mA.
The P6 (4 mA) register can be set greater than the P7 (20 mA) register, to create a reverse acting output.
The limits are –20% to +120% full scale, but P6 and P7 cannot be set equal.

Data Entry

Refer to the Step by Step table below for detailed instructions.

These registers are entered in the current Engineering Unit used by the gauge. (The current Engineering
Unit is illuminated during edit of these registers.) For example, if the gauge is set to read in InH
20°C), and a value of 110 is put into the P6 register, the SET1 relay will energize at 110 InH

SetPoint & Current Loop Models Only

O (at

2

O (at 20°C).

2

In Program Mode, the indicators “SET1”, “SET2”, and “4-20mA” will illuminate as appropriate to assist
in identifying the register. For example, when scrolling to and/or editing P6, “SET1” will be illuminated,
indicating that SET1 is being edited. Likewise for P7 and “SET2”. Also, “4-20mA” will be illuminated if
the gauge is a Current Loop model, to indicate that the 4-20mA range is being edited.

Automatic Update

If the Engineering Unit is changed, the value in the P6 and P7 registers will automatically change to reflect
the new Engineering Unit. This allows changing the Engineering Unit in Measure Mode without affecting
the outputs. For the above example, changing the Engineering Unit to inches of mercury will automatically
update the P6 register to energize at 8.077 inches of mercury, which is equivalent to 110 InH

Also, if the water density reference temperature (P3) is changed, and the current Engineering Unit is water
column based, these registers will update as appropriate. For the above example, changing the reference
temperature to 4°C will automatically update the P6 register to energize at 109.81 InH
equivalent to 110 InH

O (at 20°C).

2

QUICK REFERENCE: P6/P7, SETPOINTS

Px

Name Description Value Range Notes

P6 SET1

SetPoint model:

Controls SET1 relay.

–20% to +120%
of Full Scale

Current Loop model:

Sets 4.00 mA value.

P7 SET2

SetPoint model:

Controls SET2 relay.

–20% to +120%
of Full Scale

O (at 20°C).

2

O (at 4°C), which is

2

User defined
values.

On Current
Loop models,
SET1 cannot
equal SET2.

Current Loop model:

Sets 20.00 mA value.

13

STEP BY STEP: P6/P7, SETPOINTS

Step Action Display

1

2

3

4

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Down↓) will reset the scroll to P0

and

Press PRGM/Enter→ to open the register.

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P6” or “P7”.

Also, “SET1” or “SET2” respectively is
displayed to help identify the register, in addition
to “4-20mA” for Current Loop Models.

The display will show the current value, with the
first zero flashing for edit.

5

Press the Up↑ or Down↓ keys repeatedly to scroll

“_xxx”, where “_” is the digit being edited.

to the desired numeric value for the flashing digit.

The Zero function (Up↑
register to 0000 and allow editing to continue. The decimal
point and negative sign will not be affected, and same digit will
be flashing.

6

7

Press the PRGM/Enter→ key to accept the digit.

Repeat steps 5 and 6 for all the remaining digits.

Down↓) will reset the entire

and

The next digit begins flashing for edit.

After Enter→ when the last digit is flashing, the
decimal point flashes for edit.

The Backspace← key will backup one digit at a time, or abort
and close the register if the first digit is flashing.

The PRGM/Enter→ key will accept one digit at a time, moving
to the next, or accept the complete value and close the register
after the decimal point edit.

Please read carefully note 4 on page 11.

8

9

10

Notes

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired decimal point position, and to select
positive/negative.

If the Zero function (Up↑
point editing, it will still reset the register’s value to 0000, and
not affect the decimal point position or negative sign.

Down↓) is used during decimal

and

Press the PRGM/Enter→ key to accept the
complete value.

Press the Backspace← key to activate the register

Decimal point moves accordingly.

Please read carefully note 4 on page 11.

Negative Sign activates and de-activates when the
decimal point sequence is scrolled through
completely.

The value is accepted, and the register is closed.
Display shows “P6” or “P7”.

Normal Pressure Display.

setting and return to Measure Mode.

Please refer to the “notes” section for P4 (User Scale) on page 11. The editing process is the same.

14

P8 – DEADBAND

This register is found on the SetPoint model only. It sets the adjustable deadband for the SPDT relays. Deadband
can be set to 0%, 0.1, 0.2, 0.5, 1, 2, 5 and 10% of full scale. The relay will energize precisely at the value in its
corresponding P6 and P7 registers on increasing pressure. The relay will de-energize at a value equal to the
corresponding P6 and P7 register, minus the deadband value, on decreasing pressure. With a 0% deadband setting,
the relays will energize and reset precisely at the values in the corresponding P6 and P7 registers. During
programming, the choices found in the register correspond to the actual deadband values in percent full scale.

SetPoint Model Only

QUICK REFERENCE: P8, DEADBAND

Px

Name Description Value Range Notes

P8 Deadband Sets the amount of deadband in

percent of full scale for relays.

0, 0.1, 0.2, 0.5, 1,
2, 5, 10% FS

STEP BY STEP: P8, DEADBAND

Step Action Display

1

2

3

4

5

Gauge should be in the normal Measure Mode. Normal Pressure Display.

Press the PRGM/Enter→ key.

If the lockout is active, the gauge will now prompt for entry of
the lockout code. Refer to “STEP BY STEP: ENTERING A
LOCKOUT CODE (When Prompted)” on page 16.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register.

The Zero function (Up↑
and allow selection to continue.

Press PRGM/Enter→ to open the register.

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired register value.

The Zero function (Up↑
default and allow editing to continue.

Down↓) will reset the scroll to P0

and

Down↓) will reset the scroll to

and

The PRGM annunciator shows at the top of the
display, and the display shows the register name
“P0”.

Display shows “P8”.

The display shows the current value.

All available choices are scrolled.

(Choices indicate actual Deadband in percent of
full scale.)

SetPoint model only.
0 = Disabled.

6

7

Notes

Press the PRGM/Enter→ key to accept the desired
value.

Press the Backspace← key to activate the register
setting and return to Measure Mode.

1. After steps 2 and 3, the Backspace← key will abort the process and return to Measure Mode.

2. After steps 4 and 5, the Backspace← key will abort the edit and close the register.

3. After step 6, the PRGM/Enter→ key will again open the register for edit.

4. During any programming operation, if there is no keypad activity for approximately 1 minute, the
operation is aborted and the gauge returns to Measure Mode unchanged.

The value is accepted, and the register is closed.
Display shows “P8”.

Normal Pressure Display.

15

LOCKOUT CODE PROMPT

DESCRIPTION

When a gauge is “locked” for security purposes, it does not allow access to change its operating state
without first providing the lockout code. A gauge is “locked” by entering a lockout code in register P0
(See “STEP BY STEP: P0, LOCKOUT CODE” on page 6).

After pressing a key on a locked gauge for a desired function (ZERO, ENG UNITS, PRGM), “L 00” will
appear on the display, with the first 0 flashing. This is the prompt to enter the lockout code (similar to a
password).

VIEW-ONLY STATUS

If a user attempts to enter Program Mode without providing a correct lockout code (password), the gauge
briefly provides an error message, and then enters a “view-only” status, denoted by the PRGM indicator
flashing. In this mode, all registers (except the lockout code register itself) can be viewed, but not changed.

In this view-only status, the operator navigates through the registers exactly the same as if programming the
registers. However, the keys that would change a value are simply ignored by the gauge. Thus, the
PRGM/Enter→ key will open a register normally; the Backspace← key will close the register, and then
return to Measure Mode as expected.

STEP BY STEP: ENTERING A LOCKOUT CODE (When Prompted)

Step Action Display

1

2

3

4

After attempting to re-zero, change Engineering
Units, or enter Program Mode...

Press the Up↑ or Down↓ keys repeatedly to scroll
to the desired numeric value for the flashing digit.

Press PRGM/Enter→ key to accept the digit.

Repeat steps 2 and 3 for the second digit. The complete 2-digit value will be accepted.

The display will prompt “L 00” with the first zero
flashing for edit (indicating Lockout Code 00).

“L x0”, where “x” is the digit being edited.

The next digit begins flashing for edit.

If the correct code was entered, the gauge will perform the requested function. Otherwise, an
error message is displayed, and the gauge either returns to Measure Mode, or enters a “view­only” status for the programmable registers (if Program Mode was requested).

Notes

1. After step 1 or 2, the Backspace← key will abort the process and return to Measure Mode.

2. After step 3, pressing the Backspace← key will abort the current digit and backup to the first digit.
Another Backspace← will abort the process and return to Measure Mode.

3. Between steps 1 and 4, the Zero function (Up↑ + Down↓) will clear the entire entry to “00” again.

4. Between steps 1 and 4, if there is no keypad activity for approximately 1 minute, the operation is
aborted and the gauge returns to Measure Mode unchanged.

16

SERIAL PORT SERVICE

The 2110P Smart Gauge SetPoint models and Current Loop models provide RS-232C communication capability.
To use the serial service, connect a standard “dumb terminal” (or personal computer with terminal software) as
shown in the wiring diagram on page 20. Set the terminal communication for 9600 baud, 8 data bits, no parity, one
stop bit, and no handshaking. The terminal should be able to display at least 24 lines and 70 columns.

THE MENU

All programmable items of the gauge are available from the menu. Included with the menu is all current
data representing the current programming and operating status.

A sample view of the menu is shown below for reference. The top line identifies the gauge, firmware
revision, and copyright. The second line identifies the model (SetPoint, Current Loop), the full scale sensor
range, and the sensor identifier. Next is a reminder notice to the operator (explained below).

The Engineering Unit section is next. The first line shows the full scale for the current Engineering Unit,
which also identifies the current Engineering Unit. All available Engineering Units are shown with a
menu-selection number; the Engineering Unit is changed by simply selecting its corresponding menu­number at the terminal keyboard.

Finally, all programmable registers and functions are formatted on the menu. The menu item includes its
menu-selection character, and the current register data as applicable. To change an item, simply select its
character from the terminal keypad; the appropriate sub-menu, notes, and instructions are presented for
operator entry. Note that the serial menu typically provides more flexibility for entering data values,
compared with the gauge’s keypad (for example, more decimal digits of resolution are available).

SmartGauge/2110P (v4.00). (c)Copyright 1998 Meriam Instrument.
SetPoint model. Sensor = 200.0 inH2O; ID: dn22lj16.64

---------------------------------------------------------------­Notice! Changing any value will PAUSE Gauge Operation,
which will also pause updates to the outputs and display.

---------------------------------------------------------------­Current Full Scale: 200.0 inH2O @ 20 Deg C.

1) inH2O 4) KPa 7) cmH2O 0) User Units

2) PSI 5) mBar 8) inHg

3) KGcm2 6) Bar 9) mmHg

---------------------------------------------------------------­A) P0, LockOut Code = Disabled
B) P2, Damp Rate = 0.1 Seconds (Disabled)
C) P3, Dens. H20 Ref = 20 Deg C.
D) P4, User FullScale= 1234.0000
E) P5, SetPoint Ctrl = Both Enabled
F) P6, SET1 = 30.0000 inH2O
G) P7, SET2 = 4.0000 inH2O
H) P8, Dead Band = 0.5 % Full Scale
J) ReZero Gauge
K) Restore Factory Zero
X) EXIT Interactive Menu

Select Choice:

ACCESSING THE MENU

When the gauge is powered up or reset, it will print the menu to the serial port. Also, hitting the ENTER
key from the terminal will refresh/reprint the menu. If the terminal is not connected when the gauge first
prints the menu, it will be missed; thus, if the terminal is connected after the gauge is already running, it
will show nothing. Pressing the ENTER key will establish communications and re-print the menu.

17

IMPACT ON OPERATION

Use of the serial port service is independent of the mode of the gauge, and vice versa. It is not necessary to
change to Program Mode to use any of the menu’s features, including changing Engineering Units, editing
programmable registers, and re-zeroing. The gauge continues its active operation regardless of the serial
port service, except for the pausing explained in the next paragraph. Any keypad activity from the front
panel of the gauge will also be processed regardless of the serial port status. If entries are made through the
keypad and the serial port simultaneously, the last entry received will be active.

While the serial port is actually transferring data, the other functions of the gauge are paused to allow this
task to complete. In this paused state, the display is frozen and the outputs are not updating. Typically, the
data transfers are very short (for example, printing the menu), and thus the interruption is minimal.
However, selecting a programmable register for edit will completely stop normal gauge operation, because
the gauge is awaiting the operator’s input (data value or selection from a sub-menu). During this state, the
display is blanked to prevent mis-readings. As soon as the operator selection or entry is complete, the
gauge resumes normal operation.

The Notice of “PAUSE Gauge Operation” near the top of the menu is a reminder about this explanation. It
is particularly important when a gauge is in service as an in-process instrument, since the gauge will not
respond to process conditions while it is paused.

TIMEOUT

When the menu is displayed, it has no impact on gauge operation or performance. Therefore, the menu will
remain displayed indefinitely, or until the operator takes action or the gauge is reset. When the gauge is
stopped awaiting operator input, however, the gauge’s display is blanked and the outputs are frozen (for
example, awaiting input while editing a register). In this state, if there is no terminal keyboard activity for
approximately one minute, the operation will time-out, and the gauge is returned to its operating mode.

DATA MONITORING

Selecting “X” from the menu will EXIT the menu and begin data monitoring. (If the gauge was in
Program Mode, it will be returned to Measure Mode to allow data monitoring. The “X” menu item will
include this message as appropriate, when refreshed.)

During data monitoring, every analog-to-digital conversion from the pressure sensor is displayed on the
terminal. The additional load of the continuous serial communication will slightly reduce the overall
performance of the gauge. The resulting data rate will typically be about ten (10) conversions per second,
depending on various operating conditions. Note that the data sent to the terminal will be damped
according to the damp rate set in register P2 (see page 8).

The data includes the pressure value and Engineering Units, as well as the output status as appropriate
(SET1 ON, SET2 ON, or the 4-20 mA value). Note that this status indication is the internal calculated
value, as there is no feedback hardware on the gauge. Finally, “Over Pressure!” is indicated if the input
pressure exceeds 120% of the full scale sensor range (this indication acts immediately, regardless of the
damp rate setting).

If the gauge is taken out of Measure Mode, the data monitoring function will pause with a message. (The
menu is available at this time, as it is at any time, by hitting ENTER from the terminal.) When the gauge is
returned to Measure Mode, if the menu was not activated, data monitoring will automatically resume.

Data logging can be accomplished be invoking the appropriate logging function of the terminal software.

To EXIT the data monitoring function, simply hit ENTER on the terminal to restore the menu.

LOCKOUT

If the lockout feature is active (see register P0, page 6), the serial menu will prompt for the lockout code
when necessary. For security purposes, an asterisk (*) is displayed instead of the character as it is typed.
When entering a new lockout code through the serial port, however, the code is displayed as it is typed,
since there is no confirmation step.

18

ERROR CODES

All model 2110P gauges have an error/message feature to inform the operator of problems with the operation or
programming of the gauge. These Error Codes and messages are identified and described in the table below.

ERROR DESCRIPTION

“OP”

E001

E002

E003

E004

E005

E006

E010

Overpressure warning. The measured pressure exceeds the full scale pressure by
20% of full scale or more (high or low) . Sensor is at risk of permanent damage!

Automatic Shutoff timer has expired (Battery model only); gauge is shutting down
normally.

Requested ZERO value is not within 5% of full scale pressure, and therefore ignored.

Requested SET1 or SET2 is out of range. Must be greater than –20 % Full Scale (or

0.0 for absolute gauges), and less than +120 % Full Scale.

Requested SET1 or SET2 is equal to the other on Current Loop models. This
configuration is not acceptable. If you are attempting to disable the output, simply
set programmable register P5 to 0 (see page 12).

Requested User-Units Full Scale range is less than or equal to 0.0. Value must be
greater than 0.0.

User Entered incorrect Lockout Code. Gauge is locked. A view-only status will be
entered if Program Mode was requested (see page 16).

Full Scale Range for Engineering Units selected is beyond scale of display (>19,999).
This message would be seen, for example, during reset/power up of a 2000 PSI gauge
with InH2O (20oC) last selected, since the corresponding full scale display of
55,459.6 InH2O will not fit on the 4½ digit display.

E020

Low Battery (or power supply) Warning. This error will show repeatedly
approximately every 10 seconds, so long as the voltage supply remains low.

E030*

EEProm Error. Display alternates between “E030” and a sub-error code.

* Error codes of 030 and above indicate hardware or other internal problems; if the problem
cannot be corrected by cycling the input power supply on and off, please take note of the error
code and operating conditions, and contact Meriam Instrument at [phone].

19

INSTALLATION AND WIRING

Differential pressure
sensors have two
pressure connections on
the back of the gauge.
The diagram at the left
shows the correct
connections to obtain the
desired type of pressure
measurement. Gauge­Isolated and Absolute­Isolated pressure gauges
have only one pressure
connection.

The SetPoint model
utilizes the multi-function
terminal strip shown at
the left. This terminal
strip has a NEMA 1
rating. SPDT relays are
not powered by the gauge
internally. Jumpers from
the 24Vdc, 110Vac or
220Vac power sources
can be used if required.

The Current Loop
model uses a cannon
connector that is
designed to meet NEMA
4X requirements. The
diagram at the left shows
the terminal arrangement.
Wiring schematics for the
three and four wire, 4 to
20 mA loops are shown
on page 21.

Note: The Smart Gauge comes with a 3/16” stainless steel 1/8” FNPT pressure port(s). The
Smart Gauge should be panel-mounted or held firmly in one hand while a small wrench is used
to tighten the 1/8” MNPT pipe thread. DO NOT USE the large nut holding the pressure
connection in the bulkhead to hold the Smart Gauge while the pressure connector is installed. If
the bulkhead nut is loosened, it is possible for the sensor and sensor board to be turned inside the
Smart Gauge body. This can damage the sensor board.

20

Current Loop Model Loop Wiring

+24V

R

+Loop

-Loop

-24V

or GRD

Three wire from negative (-) supply: sink

R = Receiving device

Power supplies can

be 15 to 28 Vdc

OUTLINE DIMENSIONS

Three and four wire 4 to 20 mA loop diagrams

+24V

+

24V

50mA (min)

-

+24V

+Loop

-Loop

R

+

-

-24V

Four wire, non grounded system

+Loop

-Loop

-24V

or GRD

Three wire from positive (+) supply: source

24V

20mA (min)

R

+

24V

50mA (min)

-

+

24V

30mA (min)

-

PANEL MOUNTING CUTOUT DIMENSIONS

3.60" +/- 0.010
(92)

3.60" +/- 0.010
(92)

( ) DIMENSIONS IN MILLIMETERS

Panel Mounting

1. Make a ¼ DIN panel cutout per drawing.

2. Remove the two 6-32 socket head screws in the

grooves at the rear of the gauge.

3. Slide the panel mount jacks out of the groove.

4. Insert the gauge through the front of the panel.

5. From the rear, insert the panel mount jacks in the

grooves on the side of the gauge, and slide them
firmly against the panel.

6. Replace the two 6-32 socket head screws in the

grooves behind the panel mount jacks.

7. Tighten the panel mount jack against the panel

with the two socket head screws.

8. Refer to the note on page 20 when making

pressure connections.

21

PRODUCT SPECIFICATIONS

TYPE & RANGE:

DN: Differential Non-isolated 20”, 200", 2000" w.c.
GI: Gauge Isolated 20, 200, 2000 PSI
AI: Absolute Isolated 900 and 2000 mm Hg

MEDIA COMPATIBILITY: Non-isolated sensor for
clean, dry, non-corrosive gases. Isolated sensor for
fluids compatible with 316SS.

ACCURACY*: ± 0.05% of Full Scale (includes
combined effects of linearity, repeatability, hysteresis
and temperature). AC-powered gauges require 15
minute warm-up. NIST certification supplied.

* ± 0.10% Full Scale for DN0020 20” w.c. sensor.

ZERO DRIFT: ± 0.015% of full scale. Zeroing prior

to measurement eliminates this effect.

TEMPERATURE:

Storage: -40 °F to 140 °F (-40 °C to 60 °C)
Operating: 23 °F to 122 °F ( -5 °C to 50 °C)

PRESSURE LIMITS: Twice range for AI and GI
sensors. Twice range for DN sensors when
pressurized on high side only; 150 PSI (10.5 Kg/cm²)
static when applied to both sides of the sensor
simultaneously.

DISPLAY: 4 1/2 digit, 0.6 inch (15.24 mm) LCD.

PRESSURE CONNECTIONS: 1/8" female NPT.

Brass on non-isolated, 316SS on isolated sensors.

POWER/OUTPUTS: SetPoint model is standard with
selectable 110V AC 50/60 Hz, 220V AC 50/60 Hz, or
24V DC power. Included are an RS 232C interface
and two programmable SPDT relays, rated 1.0 amp
resistive @ 24V DC, 0.5 amp resistive @ 115V AC.

Option 1: Lithium Battery model with field­replaceable battery board, automatic shut-off
(programmable), and designed for intrinsic safety.
No outputs available.

Option 2: Current Loop model with 4-20mA
output, 24V DC (50mA) power and RS 232C.

ENCLOSURE: 4 lbs. 1/4 DIN (3.8" X 3.8" X 6.5")
aluminum enclosure with epoxy finish. Standard
model is NEMA 4X on front panel only. Battery and
Current Loop models are NEMA 4X throughout.

MOUNTING: 1/4 DIN panel mounting standard.
Options: 2" pipe mount bracket; or portable handle.

PROGRAMMABLE REGISTER QUICK REFERENCE

Px

Name Description Value Range Notes

Lockout Code Lockout for security. 00 to 99 00 = Disabled.

P0

Timeout Automatic shutoff in minutes of keypad

P1

Damp Rate Exponential damping time in seconds. 0.1, 0.2, 0.5, 1, 2, 5,

P2

Density of Water

P3

Reference
Temperature

User Units

P4

Full Scale

SetPoint Options

P5

SET1 Controls SET1 relay or 4.00 mA value. –20% to +120% FS User defined value.

P6

inactivity.

Sets reference temperature for water
density when gauge is set for water
column units.

Enables gauge to display units other
than factory defined Engineering Units.

SetPoint Model: defines which relay
outputs are active.

Current Loop Model: defines the status
of the 4 - 20 mA output.

0 (disabled), 1, 2, 5,
10, 15, 25

10, 15, 25, 50

20°C, 4°C, or 60°F

0 to 9,999 (Keypad)
0 to 19,999 (Serial)

0 = Disabled.
1 = SET1 only.
2 = SET2 only.
3 = Both enabled.

0 = 4-20 disabled
1 = 4-20 enabled

Battery model only.

0.1 = No Damping.

User defined value.

Not found on
Battery model.

SET2 Controls SET2 relay or 20.0 mA value. –20% to +120% FS User defined value.

P7

Deadband Sets the amount of deadband in percent

P8

of full scale for relays.

0 (disabled), 0.1,

0.2, 0.5, 1, 2, 5, 10%

SetPoint model
only.

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