FM Approvals Canadian Standards Association Atmosphères ExplosiblesEuropean ConformityIECEx Approval


  • Fully-Approved Explosion-Proof Modbus Scanners
  • Modbus Master, Slave, or Snooper Mode
  • 0.4" (10.2 mm) 7 Alphanumeric Characters Lower Display for Process Variables, Custom Units, and Tags
  • 5-Digit Decimal Display (ProtEX-MS2) or Feet & Inches Display (ProtEX-MFI)
  • Display Mountable at 0°, 90°, 180°, & 270°
  • SafeTouch Through-Glass Button Programming
  • Scan up to 16 Modbus Process Variables
  • Independent Scaling, Tag, and Unit for Each PV
  • Backlight Standard on All Models
  • Isolated 4-20 mA Output Option
  • Two Isolated Pulse Outputs Standard, Up to 5 kHz
  • Operating Temperature Range: -40 to 75°C (-40 to 167°F)
  • FM Approved as Explosion-Proof / Dust-Ignition Proof / Flame-Proof
  • CSA Certified as Explosion-Proof / Dust-Ignition Proof / Flame-Proof
  • ATEX and IECEx Certified as Explosion-Proof
  • Conformal Coated PCBs for Dust and Humidity Protection
  • Password Protection
  • Data Logging Functions and Modbus Accessible Data
  • Free ScanView EX Programming Software
  • On-Board Three-Wire Isolated RS-485 with Modbus RTU
  • Wide Viewing Angle
  • Flanges for Wall or Pipe Mounting
  • Explosion-Proof, IP68, NEMA 4X Enclosure
  • Three 3/4" NPT Threaded Conduit Openings (One Plug Installed)
  • 2" U-Bolt Kits Available
  • Stainless Steel Tag Available
  • 3-Year Warranty


The explosion-proof ProtEX-MS2 and ProtEX-MFI Super Snoopers are serial input RS-485 Modbus® RTU scanners. These Modbus devices are ideal for hazardous areas or safe areas in need of a rugged solution.

The PD6830X carries major approvals including:

  • FM Approved as Explosion-Proof / Dust Ignition-Proof / Flame-Proof
  • CSA Certified as Explosion-Proof / Dust Ignition-Proof / Flame-Proof
  • ATEX and IECEx Certified as Flame-Proof and Protection by Enclosure

The ProtEX-MS2 has a two-line decimal display. The ProtEX-MFI top line displays level in feet and inches up to 399 ft, 11 and 15/16 inches. It includes a 20 segment tank level indicator.

Each scanner can accept up to 16 Modbus process variables (PVs), from up to 16 devices. The scanners automatically cycle through the PVs, with the ability to manually cycle PVs or pause scanning.

Up to four math channels (CV1-CV4) may be used to perform math functions on any of the input variables. Math functions include sum, difference, weighted average, ratio and more. Nested math functions may be used in these math equations, allowing for complex math functions.

The display is programmable to show any input, math channel, units, or tags, on a variety of display combinations between the top and bottom displays.

Standard features include SafeTouch through-glass buttons for operating the scanner without removing the cover, a backlight that makes the display mode visible in any lighting condition, 511 points of input data logging, and two open collector pulse or alarm outputs. A 4-20 mA output is available as an option.

The enclosure is provided with three threaded conduit holes and integrated pipe or wall mounting flanges. One conduit plug is installed, and included in the explosion-proof approvals.

Free, PC-based, ScanView EX software that connects to the scanner via the PDA8068, PDA7485-I, or the PDA8485-I is available for programming and setup of the instrument.

The instrument can also be programmed using the four SafeTouch through-glass buttons, without removing the cover, or with four internal push-buttons.

The PD6830X includes on-board data logging of up to 511 points.


Decimal Display: Top Display: Five Digits (0 to 99999), 0.7" (17.8 mm) high, 7-segment, automatic lead zero blanking.
Bottom Display: Seven Characters, 0.4" (10.2 mm) high, 14-segment, automatic lead zero blanking.
Symbols: High alarm, low alarm, SafeTouch button sleep mode/disable, password lock.
Feet & Inches Display: Top Display: Feet & Inches, 0.60" (15.2 mm) high, 0 to 399FT, 11 15/16 IN, 7-segment, programmable 1/16 or 1/8 fraction display.
Bottom Display: Seven Characters, 0.4" (10.2 mm) high, 14-segment, 7-digits.
Tank Level Indicator: 20-segments, F (Full) and E (Empty)
Alarm Indication: High and low alarm
Backlight: White
Display Assignment: Top and Bottom Display*: Process Variables (PV); Alternating PV and Units, Tag and PV, or Tag, PV, and Units.
Bottom Display: All Top Display Options or Off
Units and tag independent for each PV.
*On feet and inches display models, top display used only for level Modbus process variables or math channels.
Backlight: White; it can be disabled/enabled in the Advanced - System menu. The backlight is automatically turned off below -20°C.
Alarm Indication: Flashing display plus HI/LO indicators
Scan and Update Rate: Ambient > -20°C: Modbus PV scan rate programmable from 2 to 99 seconds per PV. Tag and units programmable for 1 to 5 second alternation.
Ambient < -20°C: All Modbus scan, alternating units and tags 1 update/10 seconds minimum.
Underrange: Upper Display: Decimal display flashes -9999
Level display flashes to 399FT 11 15/16 IN
Lower Display: Flashes -999999
Overrange: Upper Display: Decimal display flashes 99999
Level display flashes to 399FT 11 15/16 IN
Lower Display: Flashes 9999999
Programming Method: Four SafeTouch through-glass buttons when cover is installed. Four internal push buttons when cover is removed. Free ScanView EX software.
Password: Restricts modifications of programmed settings to require re-entering the password to make changes.
Input Power: 9-30 VDC, 2.2 W
Data Logging: Up to 512 records, recorded 4/day at specific times or at defined time intervals. Record contains first eight enabled Modbus PVs; C1-4 if enabled; date, time, and log number.
Isolation: All Models: 500 V power-to-RS-485 serial communications
-AXA Models: 500 V power-to-analog output
Environmental: Operating temperature range: -40 to 75°C;
Storage temperature range: -40 to 75°C;
Backlight deactivated below temperatures ≈ -20°C;
Relative humidity: 0 to 90% non-condensing
Printed circuit boards are conformally coated.
Non-Volatile Memory: All programmed settings are stored in non-volatile memory for a minimum of ten years if power is lost.
Connections: Screw terminals accept 12 to 22 AWG wire
Enclosure: Explosion-proof die-cast aluminum with glass window, corrosion resistant epoxy coating, copper-free (0.3%)
Color: blue.
NEMA 4X, 7, & 9, IP68.
Conduit connections:
Three ¾" NPT threaded conduit openings.
One ¾" NPT metal plug with 12 mm hex key fitting installed.
Additional conduit opening configurations and plugs may be available; verify quantity and sizes on specific device labeling during installation.
Mounting: May be mounted directly to conduit. Two slotted flanges for wall mounting or NPS 1½" to 2½" or DN 40 to 65 mm pipe mounting.
Display Orientation: Display may be mounted at 90° increments up to 270° from default orientation.
Overall Dimensions: 5.67" x 5.24" x 4.88" (W x H x D) (144 mm x 133 mm x 124 mm)
Weight: 5.00 lbs (80 oz, 2.27 kg)
Warranty: 3 years parts and labor. See Warranty Information and Terms & Conditions for complete details.

Modbus Operating Modes

Master: Processes and displays data read from Modbus RTU slave devices. Up to 16 process variables (PVs) from up to 16 slave devices. Each PV programmed individually.
Slave: Processes data sent to it from a Modbus RTU master device.
Note: Refer to Modbus Register Tables for details.
Snooper: Listens to the Modbus traffic and picks up a specific register or registers being polled by a Master device from a specific slave device and processes the data being read. Up to 16 process variables (PVs) from up to 16 devices. If multiple registers are polled by the master with one command, only the first returned value will be read.
Master Poll Time: 0.1 to 99.9 sec. Time between read-commands.
Master Timeout: 0.1 to 99.9 seconds. Time elapsed after a poll request is made before the scanner considers that request to have failed.
Number of Retries: 1-99. The number of retries the scanner will make when requesting data before reporting an error condition on the PV.
Snooper Response Time: 0.1 to 99.9 seconds. Time since the last PV update the before being considered an error.
Slave Timeout: 0.0 to 99.9 seconds. Time elapsed after the last data received from a master before the scanner considers the data to be out of date. Programming 0 disables the timeout, and PV data will be displayed indefinitely despite not being updated regularly.

Serial Communications

Protocol: Modbus® RTU
Scanner ID: 1 – 247. Specifies the address of the PD6830X.
Baud Rate: 1,200; 4,800; 9,600; 19,200; 38,400; 57,600; or 115,200 bps
Transmit Time Delay: Programmable between 0 and 199 ms
Parity/Stop Bit: Even, odd, none with 1 stop bit, or none with 2 stop bits
Byte-to-Byte Timeout: Max of 1.5 character times or 750 μs
Note: Refer to Modbus Register Tables at for details.

Modbus Scanner Process Variables

PV Inputs: Up to 16 independently programmed Modbus process variables (PVs) may be scanned (Master mode) or detected (Snooper mode). Each of the 16 Modbus PVs may be enabled or disabled.
Slave ID: Specifies which device on the bus to monitor. Valid for Master and Snooper modes only.
Assign the slave ID or address (1-247) of each of the devices containing the process variables to be displayed (Slave ID for PV1-16).
Register Number: Specifies which register(s) to read in the devices on the bus.
5 Digit Function 03: 40001–49999; 04: 30001–39999; or 65: 1–9999.
6 Digit Function 03: 400001–465535 or 04: 300001–365535; or 65: 1–65535.
Range is dependent on Function Code selection (03, 04, or 65)
Will read 2 registers for Long integer and Floating point data types; the register entered and the next consecutive register number.
Valid for Master and Snooper modes only.
Function Code: 03, 04, and 65 (used to read 32 bit registers). Master & Snooper modes only.
Data Type: Select the data format of the PVs.
Select between short integer (2 byte), long integer (4 byte), or floating point (4 byte). Slave mode uses floating point only.
Byte Order: Integer data programmable as binary or BCD, and signed or unsigned.
Byte order selectable as big-endian (1234), little-endian (4321), byte swap big-endian (2143), or byte swap little-endian (3412).
Byte swap unavailable for short.

Math Channels

Math Result Channels: Four math channels CV1-CV4. Each math channel may be programmed for a math function.
Math Functions: Parameter 1 (PAR1), parameter 2 (PAR2), and parameter 3 (PAR3) independently programmable for each math channel C1-C4.
Math FunctionFunctionSetting
AdditionPAR1 + PAR2SUM
DifferencePAR1 - PAR2DIF
MultiplicationPAR1 * PAR2MULTI
Absolute DifferenceAbs(PAR1 - PAR2)DIFABS
Weighted Average((PAR1 – PAR2)*PAR3) +PAR2WAVG
Draw((PAR1 / PAR2) – 1) * PAR3DRAW
Ratio(PAR1 / PAR2) * PAR3RATIO
ConcentrationPAR1 / (PAR1 + PAR2) * PAR3CONCEN
Long IntegerConstantLONG
Floating PointConstantFLOAT
Absolute ValueAbs(PAR1)ABS
Square Root√(PAR1)SQrt
Parameter Selection: Parameter 1 (PAR1), parameter 2 (PAR2), and parameter 3 (PAR3) selectable as: Modbus PV1-16, math channel C1-4 or any math function.
Parameter Nested Math: Defining parameter 1 or 2 as a math function will prompt for level 2 parameter 1 (L2P1), level 2 parameter 2 (L2P2), and/or level 2 parameter 3 (L2P3). Level 2 parameters function identically as parameter 1 and 2 for nested math functions.

4-20 mA Transmitter Output

Output Source: Modbus PV 1-16, math channel 1-4, or disabled
Scaling Range: 4.000 to 20.000 mA for any display range.
Disable: If disabled, the output will output 3.2 mA
Calibration: Factory Calibrated: 0.0 to 1000.0 = 4-20 mA output
Underrange: Output Underrange: 3.8 mA
Overrange: Display Overrange: 20.5 mA.
Output Overrange: 20.5 mA
Accuracy: ±0.05% span ±0.004 mA
Temperature Drift: 0.08 µA/°C max from -40 to 75°C ambient
External Loop Power Supply: 30 VDC maximum
Output Loop Resistance:
Power SupplyMinimumMaximum
24 VDC10 Ω750 Ω
30 VDC100 Ω1100 Ω
Note: loop-powered backlight subtracts 150Ω from maximum resistance figures above.

Open Collector Outputs

Output Assignment: Two open collector pulse outputs.
Individually programmable for Modbus PV, math channel, constant timed pulse output; quadrature outputs (requires Out 1 and Out 2), or off.
Rating: Isolated open collector, sinking NPN, 30 VDC @ 150 mA max.
Alarm Output: Alarm Output Assign to Modbus PV 1-16 or math channel 1-4, for high or low alarm trip point.
Alarm Deadband: 0-100% FS, user selectable
Alarm Acknowledge: Front panel ACK button resets output and screen indication.
Pulse Output Count: The pulse output count (COUNT) is programmable from 0.000001 to 9999999. PV and math channels generate a frequency equal to the PV or math value divided by the Count value.
Pulse Output Pulse Width: Unless otherwise stated, pulses are 50% duty cycle for required frequency.
Pulse Output Maximum Frequency: 5 kHz, pulse width at 50% duty cycle. If the outputs exceed 5 kHz, the scanner will display PULSE OVERRNG
Quadrature Output: Output set to quadrature will lag the other pulse output by 90° (1/4 duty cycle) at output frequency. Minimum 1 Hz
Timer Output: Programmable on and off time, repeating cycle. Minimum period 0.1 second, maximum 100,000 seconds. Minimum pulse time 0.01 second, maximum 10,000 seconds.

ScanView EX Programming Software

System Requirements: Windows® 7/8/10 (Windows 32-bit or 64-bit operating systems)
Communications: PDA8068 Meter-to-USB Adapter for programming,
PDA7485-I RS-232 to RS-485 Isolated Converter (Cable not included),
PDA8485-I USB to RS-485 Isolated Converter (Cable not included).
Protocol: Modbus RTU
Scanner Address: 1-247
Baud Rate: 1200 bps to 115,200 bps
Configuration: Configure one scanner at a time.
File format: Saved as “.mve".
Printing: Configuration can be printed.
Monitor file format: Saved as ".mcf".
Data Logging Report: Saved as “.csv” file format.

Product Ratings & Approvals

Explosion-Proof for use in:
      Class I, Division 1, Groups B, C and D
Dust Ignition-Proof for use in:
      Class II/III, Division 1, Groups E, F and G; T6
Flame-Proof for use in:
      Class I, Zone 1, AEx d Group IIC; T6
Protection by Enclosure:
      Zone 21, AEx tb IIIC; T85°C
      Ta = -40 to 75°C
      Enclosure: Type 4X, IP66
      Certificate Number: 3040391
CSAExplosion-Proof for use in:
      Class I, Division 1, Groups B, C and D
Dust Ignition-Proof for use in:
      Class II/III, Division 1, Groups E, F and G; T6
Flame-Proof for use in:
      Zone 1, Ex d IIC T6
      Ta = -40 to 75°C
      Enclosure: Type 4X & IP66/IP68
      Certificate Number: CSA 11 2325749
Flame-Proof for use in:
      Zone 1, Ex d IIC T6 Gb
Protection by Enclosure for use in:
      Dust Atmospheres (Zone 21)
      Ex tb IIIC T85°C Db IP68
      Ta = -40°C to +75°C
      Certificate Number: Sira 10ATEX1116X
IECExFlame-Proof for use in:
      Zone 1, Ex d IIC T6 Gb
Protection by Enclosure for use in:
      Dust Atmospheres (Zone 21)
      Ex tb IIIC T85°C Db IP68
      Ta = -40°C to +75°C
      Certificate Number: IECEx SIR 10.0056X

ScanView EX Software

ScanView EX software allows for the programming and monitoring of one PD6830X or PD6730X Super Snooper Modbus Scanners. Use ScanView EX to program, monitor, and datalog using a PC. The PVs, math channels, and pulse input rate, total, and grand total may be selected to display on the monitoring screen independently, and the monitoring screen can be customized so each has a configurable unit and tag. Even the display number colors may be changed. All 16 PVs, math channels, and their units and tags may be logged. The data is logged on the PC, and is available for use in common tools like Microsoft Excel. All configuration data can be saved to a file for future use. 

Click here for more information about ScanView EX.


Example 1: Master Polling Multivariable Level Transmitters

In this application we have a system consisting of four MTS LP-Series multivariable tank level gauges connected to a PD6830-AX0-I-2 displaying product level, interface level, and average temperature. The PD6830X is setup for Master mode, and it is polling the Modbus transmitters.

Note: As a tank level indicator displaying in units of feet, a PD6830-AX0-I-L could also be considered for this applica-tion. This would display feet and inches in the upper display and includes a tank level indicator.

Example 2: Snooper Displaying Flow Rate from Modbus Flow Meters

In this application we have a system consisting of two Modbus enabled flowmeters connected to a SCADA system operated out of a control room. A Modbus PLC polls the data out of the flowmeters. A PD6830-AX0-I-2 has been added to the system as a Modbus Snooper, to provide the operators an easy to read field display near the flow lines.

The scanner displays one flow rate on the top display, and one on the bottom display. Each has an alternating tag and units for clear identification.


To access the wiring connections, remove the enclosure cover and unscrew the two captive screws that fasten the display module. Disconnect the ribbon cable and remove the display module. Power and signal connections are made to terminal blocks at the base of the enclosure. Grounding connections are made to the two ground screws provided on the base – one internal and one external.
D+RS-485 data B (non-inverting)
D-RS-485 data A (inverting)
GRS-485 shield ground
P+DC power positive terminal
COMDC power return/negative, reset contact closure common
RSTContact closure reset pull-up to 1.8 VDC
S+Signal input positive terminal
S-Signal input negative terminal
OC1+Open collector output 1 positive terminal
OC1-Open collector output 1 negative terminal
OC2+Open collector output 2 positive terminal
OC2-Open collector output 2 negative terminal
LP+4-20 mA transmitter DC power positive terminal
LP-4-20 mA transmitter regulated current output terminal



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