European Conformity

These loop-powered 1/8 DIN digital panel meters can be installed virtually anywhere to provide convenient and informative displays of any 4-20 mA signal. One of the most convenient features of these instruments is their dual line display which is typically used to display the process variable on the 5-digit alphanumeric top line and the units or a tag on the 8-digit alphanumeric bottom line. Another common setup is to display the input in one scale on the top line (such as feet) and another scale on the bottom line (such as gallons). Both of these lines use 14-segment, alphanumeric characters for clear indication of tags, units or alarm messages.

Further enhancing the display on these instruments is a 20-segment bargraph available on the PD6604 that also includes a numeric value of the percentage the bargraph represents.

There is even a model that displays level in feet and inches for customers who prefer to see their levels represented that way rather than in decimal format.

These loop-powered meters can be installed virtually anywhere because they get their power from the 4-20 mA loop and therefore require no separate power source. And they only drop 1.5 V (4.5 V with backlight), so they add very little burden to the loop. Additional features that allow these instruments to be installed virtually anywhere include a NEMA 4X, IP65 front panel, an operating temperature range of -40 to 167°F (-40 to 75°C) (for safe area products), conformally coated PCBs, and a backlit LCD that can be read in bright sunlight or dimly lit areas. Finally, there are intrinsically safe and nonincendive versions of these instruments that can be installed in hazardous areas.

Free, PC-based, software that connects to the meter via a micro USB cable is available for programming and setup of the meters. In addition, the meter can be programmed, setup and operated via the four front panel buttons. Three of these buttons can be used as function keys. In addition, a digital input is standard and is particularly useful for remote reset of the alarms or to trigger an alarm.

All models come equipped with two open collector outputs and are available with two solid state relays and 4-20 mA analog output options. The open collector outputs are useful for alarm indication or pulse output. The relays can be programmed for alarm indication, on/off control, or pump alternation.


  • 1/8 DIN Loop-Powered Process Meters with NEMA 4X, IP65 Front
  • 4-20 mA Input Displayed with ±0.02% FS Accuracy
  • 1.5 Volt Drop (4.5 Volt Drop with Backlight)
  • 0.7" (17.8 mm) 5 Alphanumeric Characters Top Display
  • 0.4" (10.2 mm) 8 Alphanumeric Characters Bottom Display
  • 20-Segment Bargraph with Numeric Percent Indication, Optional
  • Shallow Depth Case Extends Only 3.6" (91 mm) Behind Panel
  • (2) Open Collector Outputs Standard; Assigned to Pulse, Alarm, Timer, or Stopwatch
  • (2) Optional Loop-Powered Solid State Relays; Assigned to Alarm, Control, Timer, or Stopwatch
  • Stopwatch & Timer Functions to Drive Relays & Open Collectors
  • Optional Isolated 4-20 mA Analog Output
  • Relay Pump Alternation Based on Level and Runtime
  • Display Relay Runtime & Cycle Count via Relay Info Menu
  • Round Horizontal Tank Function; Just Enter Diameter & Length
  • 32-Point Linearization, Square Root Extraction and Programmable Exponent Function
  • Free PC-Based MeterView XL USB Programming Software
  • HART® Protocol Transparent
  • Loop-Powered Backlight with Red Backlight for Alarm Conditions
  • Safe Area Operating Temperature Range: -40 to 167°F (-40 to 75°C)
  • Conformal Coated PCBs for Dust & Humidity Protection
  • Password Protection
  • Wide Assortment of NEMA 4X Enclosures for up to Ten Meters
  • Light / Horn & Reset Button Accessory
  • Control Station Accessory for Remote Operation of Digital Input
  • 3-Year Warranty

Display Features

The Loop Leader’s display provides multiple ways to help users understand and keep track of their processes. The most obvious is the dual line which typically allows the user to display a numeric value of the process variable on the top line and units and/or a tag on the bottom line. There is also a bargraph that includes a numeric value of the percentage the bargraph represents. Finally, to alert users to an alarm condition, the display can turn red and flash an alarm message.

Dual-Line Display with PV/Units/Tag/Bargraph

One of the most common configurations of these instruments is displaying the process variable on the top line and units and a tag toggling on the bottom line with a bargraph for additional clarity:

PV on the top line; units and tag toggling on the bottom line

To help users get a quick understanding of where their process is at, certain Loop Leader models are available with a 20-segment bargraph. This bargraph also includes a numeric value of the percentage the bargraph represents.

Bargraph Provides Quick Understanding

To help users get a quick understanding of where their process is at, certain Loop Leader models are available with a 20-segment bargraph. This bargraph also includes a numeric value of the percentage the bargraph represents. The bargraph can be programmed to represent the percent of PV1 or PV2 or it can be scaled to any range within the scale.

Max/Min Display

The max & min readings (peak & valley) reached by the process can be displayed either continuously or momentarily:

  1. Display momentarily by pressing the F1 key (default) or assigning to any of the other function keys or to the digital input in the User menu. Press Enter to lock/unlock max/min display.
  2. Display continuously by assigning either display line to max/min through the Display menu.

Any of the F1-F3 function keys (buttons) and the digital input can be programmed to reset the max & min readings.

Dual-Scale Display Feature

Users can use the Loop Leader’s dual-scale feature when they want to show the same input in two different scales. For instance, the following example shows an application where the Loop Leader displays the input in feet and gallons:

Display Feet & Gallons and Toggle Between Units

Feet & Inches Display with Bargraph

There are Loop Leader models available for users that prefer to see their level displayed in feet & inches instead of decimal format. These versions can display level to 999FT 11IN & 15/16 on the top line. The bottom line can toggle between a tag and units or if dual scale mode is used, can display the input in a different scale such as volume.

Level in Feet & Inches with Bottom Line toggling between volume (62,346), and units (Gallons)

Predefined and Custom Units

The meter has six available preprogrammed unit classes, volume, height, temperature, pressure, weight, and rate. When the desired unit class or unit of measure within a class is not available, a custom unit may be programmed by using the (CUSTOM) menu.


The tare function zeroes out the display. In the case of scale weight, tare is used to eliminate container weight and provide net weight readings. The captured tare may be reset manually with any function key or digital input.

Change Between Units without Needing to Re-Scale the Meter

It is possible to change the display units within the selected unit class without the need to re-scale the meter. When selecting a new unit from within the DISPLAY menu (e.g. changing from gallons (GAL) to liters (L)), the meter will automatically convert the display values to display the new unit. If entering a custom unit (CUSTM), a custom conversion factor will need to be entered.

Alarms Indicated by Flashing Red Messages

When an alarm occurs, the Loop Leader’s display can be programmed to turn red and flash an alarm message along with the process variable and an alarm indicator (!). (Alarm indicator symbols are not available on bargraph models) The Loop Leader’s flashing red alarm message can be activated even if no relay or open collector is connected.


Loop Leaders are available with two open collector outputs as standard and two solid state relays and 4-20 mA output as options. The open collector outputs and relays generally operate in the same manner, with the major exception being the open collectors are not available for pump alternation and the relays are not available with pulse features. The open collectors and relays can be controlled either automatically or manually. The alarm status (with flashing red message) will show on the display even with no output wired.

Two Open Collector Outputs

The Loop Leader is equipped with two NPN open collector outputs that may be set up for pulse outputs, alarms, timed pulses, stopwatch on/off, or disabled. Pulse outputs can be set to transmit the PV value (PV1 or PV2 if meter is in dual-scale mode). Output 2 may be used to generate a quadrature output based on the other open collector output. An output test mode is also selectable to generate pulses at a constant programmable frequency.

Two Optional Solid State Relays

The meter is optionally equipped with two solid state relays that may be set up for alarms, timer, stopwatch on/off, or pump alternation. The relays are rated at 250 VAC/DC @ 1 A for resistive loads and 75 VA @ 0.6 A, 250 VAC/DC max (Safe Area only) for inductive loads. Alarms are available based on the PV value or the digital input.

Loop-Powered Relay Alarm Trip

The Loop Leader, with its two solid state relays, can be used as a loop-powered relay alarm trip. The Loop Leader’s two relays can be programmed for two different kinds of latching operation: Reset via momentary contact closure at any time or reset via momentary contact closure only after the alarm has cleared. And the Loop Leader's display can be programmed to turn red and flash an alarm message – something not found on most loop powered alarm trips.

Optional Isolated 4-20 mA Output

The isolated analog output signal can be configured to represent the process variable (PV1, PV2, or retransmit). While the output is nominally 4-20 mA, the signal will accurately accommodate underand over-ranges from 1 to 23 mA. The output can be reverse scaled such that the meter’s high calibration value outputs 4 mA and the meter's low calibration outputs 20 mA.

Resetting the Open Collectors and Relays

The open collectors and relays (alarms) may be programmed to reset in the following ways:

  • Automatic (AUTO): Alarm will reset automatically once the alarm condition has cleared.
  • Automatic/Manual (AUTO.MAN): Alarm will reset automatically once the alarm condition has cleared but can also be reset using the Enter button (or whichever function key is set to acknowledge) at any time.
  • Latching (LATCH): Alarm must be reset manually and can be done so at any time. Press the Enter (ACK) button at any time to clear the alarm.
  • Latching with Reset after Cleared (L-CLEAR): Alarm must be reset manually and can only be done so after the alarm condition has cleared. Press the Enter (ACK) button after the alarm condition has cleared to reset the alarm.


Except where noted all specifications apply to operation at +25°C.


Display: Dual-line LCD with backlight.
Both lines 14-segment alphanumeric.
Top: 0.7" (17.8 mm)
Bottom: 0.4" (10.2 mm)
Display may be programmed to turn red and flash a user-defined message on alarm condition.
PD6603 & PD6607 only: Top line: 7-segment numeric, FT-IN
Bottom line: 14-segment alphanumeric
Backlight: Powered by 4-20 mA loop. Intensity varies with signal level
Top Line: 5 digits (-9999 to 99999) or 5 characters (all capital & most lower-case letters)
PD6603 and PD6607 only: -99FT 11IN 15/16 to 999FT 11IN 15/16
Top Line Fractions: PD6603 & PD6607 Only: FT – IN/*: Automatically reducing fractions to the lowest denominator. FT-IN/16, FT-IN/8, FT-IN/4, FT-IN/2, FT-IN
Bottom line: 8 digits (-9,999,999 to 99,999,999; separated by commas) or 8 characters
(all capital & most lower case letters)
Bargraph: PD6603, PD6604, PD6607, and PD6608 only: 20 segments, numeric percent indication at top
Decimal Point: Up to four decimal places on top line and up to seven decimal places on bottom line
Note: Decimal points are not available on top line of the PD6603 and PD6607 F&I meters
Commas: Commas to indicate 1000s (e.g. 88,987,628) on bottom line
Dual-Scale Feature: The input can be displayed in different scales on the top and bottom lines. For instance, the top line could display the input in height and the bottom line could display that same input in volume.
Alarm Indication: Programmable: red backlight, flashing display, alarm symbol (!);
(symbols not available on bargraph models). Bargraph segment flashes on alarm.
Alarm Message: On or Off; user programmable, 8 characters maximum. Displayed every 10 seconds for 1 second on bottom line.
Display Update Rate: Ambient > -10°C: 1 update/second
Ambient -20 C: 1 update/2 seconds
From -20°C to -40°C the update rate slows down 1 second for every -2°C
(e.g. at -24°C, 1 update/4 seconds).
Overrange: Top: 99999; PD6603 and PD6607 only: 999 11 15/16;
Bottom: 99,999,999 (flashing)
Underrange: Top: -9999; PD6603 and PD6607 only: -99 11 15/16;
Bottom: -9,999,999 (flashing)


Environmental: Operating temperature range:
-40 to 75°C for safe area products
-40 to 70°C for hazardous area products
Storage temperature range: -40 to 85°C
Relative humidity: 0 to 90% non-condensing. Printed circuit boards are conformally coated.
Programming Method: Front panel & Free PC-based USB programming software
Enclosure & Materials: Enclosure: 1/8 DIN, IP65, NEMA 4X front panel, high impact plastic, NORYL® polyphenylene ether & polystyrene blend (PPE PS) resin, UL 94V-0, Color: gray, Gasket: silicone rubber, Faceplate: LEXAN® polycarbonate (PC) film, Buttons: silicone rubber
Noise Filter: Averages the input signal over a period of time between 1 and 16 seconds to dampen the effects of a noisy signal that causes a jumpy display.
Filter Bypass: 0.0 to 99.9% of full scale. Input signal changes that are greater than bypass value are displayed immediately.
Recalibration: Recalibration is recommended at least every 12 months.
Max/Min Display: Max/min readings reached by the process are stored until reset by the user or until power to the meter is turned off.
Tare: Tare function zeros out PV1 to accommodate for unwanted height or zeros out PV2 for weight of a container. Tare function can be assigned to a function key or a digital input.
Password: Programmable password restricts modification of programmed settings.
Non-Volatile Memory: All programmed settings are stored in non-volatile memory for a minimum of ten years if power is lost.
Normal Mode Rejection: 64 dB at 50/60 Hz
Connections: Removable screw terminals accept 12 to 22 AWG wire.
Tightening Torque: Screw terminal connectors: 4.5 lb-in (0.5 Nm)
Mounting screws: 8.0 lb-in max. (0.9 Nm)
Overall Dimensions: 4.68"x 2.45"x 3.79" (119 mm x 62 mm x 96 mm) (W x H x D)
Weight: 8.7 oz (247g) with option board
Warranty: 3 years parts and labor. See Warranty Information and Terms & Conditions on for complete details.


Input: 4-20 mA
Accuracy: ±0.02% of span ±1 count, Square root and programmable exponent: 10-100% FS
Voltage Drop: Without Backlight: 1.5 V maximum, With backlight: 4.5 V maximum
Equivalent Resistance: With backlight off: 75 Ω @ 20 mA, With backlight on: 225 Ω @ 20 mA
Input Overload: Over current protection to 1 A maximum, Over voltage protection to 30 VDC max (between mA+ and mA-/BL-)
Temperature Drift: 25 PPM/°C from -40 to 75°C ambient
Function: PV1: Linear (2-32 points), square root, or programmable exponent
PV2: Linear (2-32 points) or round horizontal tank
PD6603 and PD6607 only: PV1: Linear (2-32 points)
PV2: Linear (2-32 points) or round horizontal tank
Low-Flow Cutoff: 0.1 to 999,999 or disable. Point below at which the display always shows zero.
PD6603 and PD6607 only: 1/16 to 999 FT 11 IN 15/16 or disable. Point below at which the display always shows zero.
HART Transparency: The meter does not interfere with existing HART communications; it displays the 4-20 mA primary variable and it allows the HART communications to pass through without interruption. The meter is not affected if a HART communicator is connected to the loop. The meter does not display secondary HART variables.

Common Open Collector & Relay (Alarm) Specifications

Number: Two open collectors & two relays
High or Low Alarm: User programmable for high or low alarm
Alarm Deadband: 0-100% FS, user programmable
Output Assignment: Pulse, Alarm, Timer, Stopwatch, or Disable
Alarm Output Source: Assign to PV (PV1, PV2) or Digital Input
On & Off Time Delay: 0 to 9,999 seconds
Fail-Safe Operation: Independent for each open collector and relay. Fail-safe on, the output is on under normal conditions. Fail-safe off, the output is on under alarm conditions.
Alarm Operation: Automatic, Automatic with manual override, Latching (manual reset anytime), Latching with reset after cleared (manual reset only after alarm has cleared)
Alarm Indication: Programmable: red backlight, flashing display, alarm symbol (!); (symbols not available on bargraph models). Bargraph segment flashes on alarm.
Alarm Message: Programmable: 8 characters maximum; displayed every 10 sec for 1 sec on bottom line. May be turned off.
Alarm Acknowledge: Front panel ACK button or external digital input resets output and screen indication
Auto Initialization: When power is applied to the meter, open collectors and relays will reflect the state of the input to the meter
Timer Output: One-shot or Continuous
Off Time Delay: 1 sec to 99:59:59 (hrs:min:sec)
On Time: 1 sec to 99:59:59 (hrs:min:sec)
Stopwatch: Output turns on when started and off when stopped

Open Collector Outputs

Rating: Isolated open collector, sinking NPN 5-30 VDC @ 150 mA maximum
Output Assignment: Pulse, Alarm, Timer, Stopwatch on/off, or Disable
Pulse Output Source: PV (PV1, PV2) or Test Frequency
Pulse Output Factor: 0.000001 to 999,999.9
Pulse Width: 0.5 ms @ 1 kHz; 500 ms @ 1 Hz; 50% duty cycle
Pulse Output Frequency: 1,000 Hz maximum
Quadrature Pulse Output: Available for Output 2 (90° behind Output 1) 500 Hz max
Alarm Output Source: Assign to PV (PV1, PV2) or Digital Input

Solid State Relays

Rating: 250 VAC/VDC @ 1A resistive
75VA; 250VAC; 0.6A pilot duty (inductive) – UL Code D300
25VA; 250VDC; 0.6A pilot duty (inductive) – UL Code R300
Noise Suppression: Metal oxide varistors across outputs
Relay Assignment: Pump Alternation, Alarm, Timer, Stopwatch on/off, or Disable
Alarm Output Source: Assign to PV (PV1, PV2) or Digital Input
Pump Alternation: Relays can be programmed to alternate with each pump cycle with an elapsed time override where the pumps will alternate regardless of level. Pump alternation time can be programmed for 0 to 999:59 (hrs:min)
Relay (Pump) Runtime: Meter will keep track of how long each relay (pump) has operated and display this information
Relay (Pump) Cycles: Meter will keep track of how many times the relays (pumps) have cycled and display this information

4-20 mA Transmitter Output

Accuracy: ±0.05% FS ±0.001mA
Output Source: PV1, PV2, re-transmit; reverse scaling allowed
Scaling Range: 1.00 to 23.0 mA
Disable: High impedance state, less than 1 mA
Calibration: Factory calibrated 4.00 to 20.00 mA
Underrange: 1.0 mA, 3.5 mA, or 3.8 mA (If input < 3.5 mA), or Off; user selectable
Overrange: 20.5 mA, 20.8 mA, or 23.0 mA (If input > 20.5 mA), or Off; user selectable
Isolation: 500 V input-to-output
Temperature Drift: 0.5 μA/°C max from -40 to 75°C ambient
External Loop Power Supply: 7.0 VDC to 30.0 VDC maximum
Output Loop Resistance: 10-750 Ω @ 24 VDC; 100-1100 Ω @ 30 VDC

On-Board Digital Input

Function: Remote operation of front-panel buttons, acknowledge/reset relays, reset total, reset max/min values, etc. See User section of Display Functions & Messages in the instruction manual for a complete list of capabilities.
Contacts: 2.1 VDC on contact. Connect normally open contacts across DI+ and DI
Logic Levels: Logic High: 2.4 to 30 VDC (max)
Logic Low: 0 to 0.9 VDC

MeterView XL Programming Software

Availability: Free download from
System Requirements: Microsoft® Windows® 7 & 10
Communications: USB 2.0 (Standard USB A to Micro USB B)
Configuration: Configure all parameters on the meter. Configure meters one at a time.
Configuration Files: Generate with or without meter connected; Save to file for later use.
USB Power Connection: Meter is powered by USB connection during programming, if 4-20 mA loop is not connected.

Free Meterview XL PC-Based Programming Software

PD6622/6 Loop-Powered Rate/TotalizerPD6624/8 Loop-Powered Rate/Totalizer with Bargraph
The main screen displays an image of the connected meter and includes various information about this meter, such as model number, readings, and status.

Free, PC-based, MeterView XL software that connects to the meter via a micro USB cable is available for programming and setup of the meters. This software greatly simplifies the programming process and also allows the user to save configuration files for later use. The meter will also be powered by the USB connection so no additional power is needed during programming.

  • Free
  • Easiest Way to Program Your Loop Leader
  • Convenient USB Connection
  • Meter Powered by USB Connection During Programming
  • Save & Print Configuration Files without Meter Connected
  • Micro USB Cable Provided

Mounting Dimensions

  1. Panel cutout required: 1.772" x 3.622" (45mm x 92mm)
  2. Panel thickness: 0.040 - 0.250" (1.0mm - 6.4mm)
  3. Mounting brackets lock in place for easy mounting
  4. Clearance: Allow 6" (152 mm) behind the panel


Pump Control

Loop Leaders, when ordered with the two solid state relays, have several features that make them ideal for simple duplex pump control. The relays can be programmed to alternate the pumps based on level and runtime thus ensuring even wear on both pumps. If the level remains constant (within on/off points), alternation is based on runtime. If the level cycles the on/off points, alternation is based on level and runtime. If the run time is set to 0, alternation is based on level. The meter also keeps track of runtime for both pumps and the number of times they have cycled.

In addition to the two solid state relays for controlling pumps, the Loop Leaders two open collectors could be used to indicate high or low level alarm conditions.

Pump Alternation

The Loop Leader can be used as a pump controller to alternate two pumps and provide high and low level alarm indication. The pumps can be programmed to alternate on level and run time and the meter can display the pump run times and the number of times they have cycled. The PD6606–L2N can be used as an intrinsically safe pump controller.

Loop Leader Pump Alternation

Signal Input Conditioning

The PD6600 Loop Leader process meter allows you to select the signal input conditioner applied to the input: linear, square root, programmable exponent, or round horizontal tank volume calculation.

The programmable exponent function is used to linearize the level signal in open channel flow applications using weirs and flumes and display flow rate in engineering units.
The square root function can be used to linearize the signal from a differential pressure transmitter and display flow rate in engineering units.
The round horizontal tank linearization function automatically calculates the volume in a round horizontal tank with flat ends.

Digital Input

A digital input comes standard on the Loop Leader PD6600 Series. This allows the user to program an external button to activate certain functions immediately like alarm acknowledgement, display minimum/maximum values, tare the display, reset a value, and many more. This allows the Loop Leader to be greatly customized for use in specialized applications. See the PD6600 series manuals for all digital input functions.

Timer Function

Application Timers are used in everyday life; one of the most common examples is the microwave oven. Industrial timers are used in process control applications where certain events or actions need to be controlled by time. Examples include automatic and batch control applications, where the relay needs to be energized for a specific length of time.

The timer fuction is available on the open collector and relay outputs; which means that you can have up to four timers per meter. The start and stop actions can be triggered from the setup menu or by the function keys and digital input. The meter can be setup to display the off/on timer count down.

There are two modes of operation:

  1. Continuous Timer (Interval)
    At the start of the timer the output is off and turns on after the Off Delay elapses. The output remains on for the duration of the On Time. The cycle repeats until the user stops the timer either from the menu or a function key.
  2. One-Shot Timer
    At the start of the timer the output is off and turns on after the Off Delay elapses. The output remains on for the duration of the On Time. The timer stops and the cycle does not repeat.
  1. A sensor detects the bottle is in place and triggers the digital input to start the timer
  2. The timer output controls the filling pump
  3. The On Time is set according to the time needed to fill the bottle


Connectors Labeling

The connectors' label, affixed to the meter, shows the location of all connectors available with requested configuration.

Current Loop (4-20 mA) Connections

The following figures show a 4-20 mA current loop connected to the meter. The first figure shows the connection with the backlight disabled and the second shows the connection with the backlight enabled. The meter is powered by the 4-20 mA current loop.

Digital Input Connection

A digital input is standard on the meter. This digital input is connected with a normally open contact across DI+ and DI-, or with an active low signal applied to DI+.

4-20 mA Output Connections

Connections for the 4-20 mA transmitter output are made to the connector terminals labeled MA OUT. The 4-20 mA output must be powered from an external power supply.

Relay Connections

Relay connections are made to two four-terminal connectors. Each relay's C terminal is common only to the normally open (NO) contact of the corresponding relay.

Open Collector Outputs

Open collector output 1 and 2 connections are made to terminals labeled O1+ and O1-, and O2+ and O2-. Connect the alarm or pulse input device as shown below.


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