Features

• Fully-Approved Explosion-Proof & Intrinsically Safe Loop-Powered Meters
• 4-20 mA Input Displayed with ±0.02% of Full-Scale Accuracy
• 1.5 Volt Drop (4.7 Volt Drop with Backlight)
• 0.7" (17.0 mm) 5 Digits 7-Segment, FT-IN & Fractions Top Display (PD6907)
• 0.7" (17.0 mm) 5 Alphanumeric Characters Top Display (PD6908)
• 0.4" (10.2 mm) 8 Alphanumeric Characters Bottom Display
• Displays Level in Feet & Inches up to 999 Feet, 11 & 15/16 Inches (PD6907)
• 20-Segment Bargraph Standard
• CapTouch Through-Window Button Programming with Normal and Delayed Modes
• Loop-Powered Backlight with Red Backlight for Alarm Conditions
• (2) Open Collector Outputs Standard; Assignable to Pulse, Alarm, Timer, or Stopwatch
• (2) Optional Loop-Powered Solid-State Relays; Assignable 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
• 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
• Operating Temperature Range: -40 to 75°C (-40 to 167°F)
• Installation Temperature Range: -55 to 75°C (-67 to 167°F)
• Conformal Coated PCBs for Dust & Humidity Protection
• CSA Certified for Explosion-Proof / Dust-Ignition Proof / Flame-Proof
• ATEX and IECEx Certified as Intrinsically Safe and Explosion-Proof
• Explosion-Proof, IP68, NEMA 4X Die-Cast Aluminum & Stainless Steel Enclosures
• 3-Year Warranty

Why Use Loop-Powered Meters?

The most basic decision a user wishing to display a 4-20 mA signal on a digital display has to make is: should the meter be powered by line voltage or should it be powered by the 4-20 mA loop?

There are three main benefits of using loop-powered devices:

• No additional power required
• Easy wiring
• Additional digital displays can easily be added in the same loop

The following diagram illustrates how a loop-powered meter is wired. Notice there are only two connections made to the meter.

For more information on loop-powered meters, check out Fundamentals of Loop-Powered Devices and Loop-Powered vs Line-Powered Meters white papers.

Overview

Hazardous Area Loop-Powered Indicators with Advanced Display and Control Features

The ProtEX+ loop-powered explosion-proof & intrinsically safe meters can be installed virtually anywhere to provide convenient and informative display of any 4-20 mA signal. They can operate down to -40°C and be installed in areas that get as cold as -55°C, however the display will cease functioning. One of the most convenient features is the dual-line display, typically used to display the process variable on the 5-character alphanumeric top display and the units of measure or tag on the 8-character alphanumeric bottom display. Feet and inches models display level in feet and inches on the top display while the 8-digit alphanumeric bottom line may be used to display a tag or custom message. Further enhancing the display on these instruments is a 20-segment bargraph.

The ProtEX+ Series is CSA Certified for Explosion-Proof / Dust-Ignition Proof / Flame-Proof and ATEX and IECEx Certified as Intrinsically Safe and Explosion-Proof.

Four CapTouch through-glass buttons are available to operate the instrument without removing the cover. The CapTouch buttons have two modes of operation: Normal and Delayed, and they can be disabled for security via a switch on the display module.

All models come equipped with two open collector outputs and a digital input. There are also models available with two solid-state relays and isolated 4-20 mA analog output options. The open collector outputs are useful for alarm indication. The digital input can be used to acknowledge the relays, to start/stop a timer/stopwatch, and more. The relays can be programmed for alarm indication, on/off control, or pump alternation.

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.

For safe are versions of these instruments please click here.

Front

PD6907-HA-AL

• Feet & inches
• Aluminum

PD6908-HA-AL

• Decimal display
• Aluminum

PD6907-HA-SS

• Feet & inches
• Stainless steel

PD6908-HA-SS

• Decimal display
• Stainless steel

Connections

Display Features

PD6907 Feet & Inches Meter with Bargraph

PD6908 Process Meter with Decimal Display

Commas Make it Easy to Read Big Numbers

The bottom display is set to show a comma separating the thousands and millions place by default if a numeric value is being displayed. This feature can be disabled or enabled using the Comma menu.

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.

Backlight Turns Red on Alarm

The loop-powered backlight is standard on all ProtEX+ meters. It provides optimum visibility in any lighting condition and it can be programmed to turn red for alarm conditions. The backlight may be enabled or disabled using the Backlight menu. The backlight is enabled by default (input must be wired appropriately for the loop-powered backlight to function).

Bargraph Provides Quick Understanding

The 20-segment bargraph helps users get a quick understanding of where their process is at. The bargraph can be programmed to represent the percent of PV1 or PV2 or it can be scaled to any range within the scale.

On PD6907 models, the bargraph also includes a dynamic numeric value of the percentage the bargraph represents.

Dual-Scale Display Feature

Users can use the meter’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 meter displays the input in feet and gallons.

14-Segment Characters

Notice how much better letters like “T”, “N” and “K” appear as 14-segment characters on the bottom display vs. 7-segment characters found on other meters.

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.

Change Between Units

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.

Tare

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.

All PD6900 meters are equipped with four capacitive sensors that operate as through-window buttons so that they can be operated without removing the cover (and exposing the electronics) in a hazardous area.

CapTouch buttons are designed to work under any lighting condition and to protect against false triggering. They can be turned off for security via a switch on the display module.

To actuate a button, press one finger to the window directly over the marked button area. When the cover is removed, the CapTouch buttons can be used after the meter completes a self-calibrating routine ( flashes). The sensors are disabled when more than one button is pressed, and they will automatically re-enable after a few seconds ( off).

CapTouch Buttons Operation Modes

The CapTouch buttons have two modes of operation: Normal and Delayed.

Normal is the factory default setting. This mode is recommended for programming the meter or when immediate operation of the buttons is needed.

Use the Delayed mode to prevent accidental trigger of the buttons. In the Delayed mode, the buttons enter into a low sensitivity state (sleep) and they ignore quick button presses after 20 seconds of inactivity. To wake up the buttons, press and hold any button for more than 2 seconds, the buttons respond normally.

Turning Off CapTouch Buttons

The CapTouch buttons can be turned off for security by moving the slide switch located on the display module to the Off position.

Outputs

PD6900 meters, 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 runtime 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.

Two Open Collector Outputs

The meter 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 @ 0.5 A for resistive loads and 38 VA @ 0.3 A, 250 VAC/DC max (Safe Area only) for inductive loads. Alarms are available based on the PV value or the digital input.

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 under- and 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.

Loop-Powered Relay Alarm Trip

The two solid-state relays can be used as a loop-powered relay alarm trip in hazardous areas. The meter’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 meter’s display can be programmed to turn red and flash a unique custom alarm message for each relay – something not found on most loop-powered alarm trips.

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.

Loop-Powered Isolator

The ProtEX+ can be used as a loop-powered isolator for the 4-20 mA signal in hazardous areas with the added benefit of a digital readout to display the process variable.

PD6900 meters, 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 runtime 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 meter’s two open collectors could be used to indicate high or low level alarm conditions.

Pump Alternation Application

The PD6900 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 runtime and the meter can display the pump runtimes and the number of times they have cycled. A ProtEX+ with the –L2N option can be used as an intrinsically safe pump controller.

Pump Control with Alternation & Alarm Example

The following is a typical application where the relays and open collectors are used for pump alternation and high/low level alarm.

Step 1

Relay #2 turns the main pump on at 6,000 gallons and turns it off at 2,000 gallons. lights up to show relay 2 is energized. The indicates level is rising.

Step 2

With the Pump Alternation feature activated, the next time the level reaches 6,000 gallons, relay #1 transfers and starts the backup pump. lights up to show relay 1 is on.

Step 3

If the backup pump is not able to keep up, and the level reaches 7,000 gallons, relay #2 transfers and starts the main pump as well. Open collector #1 trips the High Level Alarm, the display turns red and flashes “Hi Level” message, and indicates an alarm condition. The High Level Alarm resets at 6,500 gallons.

Step 4

Once the level has dropped below the reset points, both relays will turn off. If the Main Pump fails to turn off, open collector #2 trips the Low Level Alarm at 1,000 gallons to warn against the pump running dry. The Low Level Alarm resets at 1,500 gallons.

Input Signal Conditioning

To satisfy applications that require scaling in ways other than the usual 2-point linear method, the meter can also be scaled for square root (differential pressure flow), programmable exponent (open channel flow) or round horizontal tank volume calculation.

For existing processes that require these linearization capabilities, one of the great benefits of loop-powered meters is that they get their power directly from the 4-20 mA loop and thus require no additional wiring. All a user has to do is break the existing loop and wire in the meter. For this reason, loop-powered meters are very easy to add to existing applications such differential pressure flow, open channel flow, or round horizontal tank volume calculation.

Round Horizontal Tank Volume Calculation

This function automatically calculates the volume in a round horizontal tank with flat ends.

Programmable Exponent Linearization

The programmable exponent can be used to linearize the signal from level transmitters in open-channel flow applications using weirs and flumes.

Square Root Linearization

The square root function can be used to linearize the signal from a differential pressure transmitter and display flow rate in engineering units. The meters in this data sheet will display flow rate only. To display both flow rate and total use the PD6928-HA.

Multi-Point Linearization

Meters are set up at the factory for linear function with 2-point linearization. Up to 32 linearization points can be selected for the scaled value under the linear function. Multi-point linearization can be used to linearize the input so the meter can display volume from non-linear tanks or to convert level to flow using weirs and flumes with complex equations.

MeterView XL software makes it easy to program up to 32 points.

Physical Features

ProtEX+ Aluminum & Stainless Steel Enclosures

NEMA 4X Enclosure

The ProtEX+ enclosure provides serious protection from the elements, high impact, corrosion, and dust. It is NEMA 4X/IP68 rated. In addition, the ProtEX+ enclosure provides protection against electrical interference and its extensive worldwide agency approvals allow it to be installed virtually anywhere.

Easy Pipe Mounting

The ProtEX+ comes with a built-in flange. This allows easy mounting to walls or pipes using either a PDA6846 Zinc Plated Steel or a PDA6846-SS Stainless Steel 2" U-Bolt Kit. A slot on the back of the enclosure makes it easy to center the unit on a pipe.

Wide Viewing Angle

The window and display module have been optimized to provide a wide viewing angle of approximately ±40°; nearly twice that of the competition.

Tamper-Proof Capability

The instrument can be made tamper-proof by inserting a wire through the built-in loop on the base of the enclosure and a hole in the lid of the enclosure and securing this wire with a lead seal.

Rotatable Display Module

The display module can be rotated in 90° increments providing added mounting flexibility. Plus the various conduit connections allow a variety of installation options.

Stainless Steel Tag Attaching Loop

The enclosure is equipped with a loop at the top to easily attach a PDA-SSTAG stainless steel tag.

USB Port for Easy Connection to Free MeterView XL Software

A USB port located on the display module allows it to be connected to a PC for use with free MeterView XL software. The meter is powered by the USB connection during programming, if a 4-20 mA loop is not connected.

Two Threaded Conduit Openings

The ProtEX+ comes with two ¾" NPT threaded conduit openings as standard. It also available with M20 conduit openings as an option.

Conduit plugs available that are sold separately include the PDAPLUG75 3/4" NPT 316 stainless steel conduit plug with approvals and the PDAPLUGM20 M20 316 stainless steel conduit plug with approvals for models with M20 conduit openings.

Operational Features

There are two ways the user can interact with the ProtEX+ to perform a variety of useful functions: programmable function keys and the digital input.

Programmable Function Keys

The three CapTouch buttons labeled F1, F2, and F3 can be programmed as function keys to perform a variety of meter functions simply by pressing on the window over the button. These include operation of the tare function, resetting the tare, resetting the meter’s relays or open collectors, starting and stopping timers, and displaying max/min values. The default settings for the function keys are:

On-Board Digital Input

A digital input is standard on ProtEX+ meters. This digital input is programmed identically to the function keys. The input is triggered with a contact closure between DI+ and DI-, or with an active low signal. For a complete list of Digital Input settings available, see Function Keys & Digital Input Available Settings in the instruction manual.