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  • WiFi interface boards are Plug & Play field installable
  • Fits all DPM-3 1/8 DIN size instruments
  • Allows DPM-3 instruments to be polled using Modbus commands
  • Can be polled every 10 msec via WiFi
  • Provides updated analog readings at up to 60 times/sec
  • Includes external 2.4 GHz WiFi antenna and 30" (76 cm) antenna cable
  • Meets IEEE 802.11 b/g/n wireless standard for data rates up to 72.2 Mbits/sec
  • Includes Mini-USB port for programming or for operation as a Modbus slave at up to 38400 baud

 DPM-3-OPT-WXU WiFi interface board


The DPM-OPT-WXU WiFi and USB communication board allows a DPM-3 1/8 DIN digital panel meter to be interfaced to an external PC or HMI via WiFi or USB. The use of WiFi, which is standard with most computers, avoids the need for communication cables.

WiFi operation complies with the IEEE 802.11 b/g/n wireless standard for data rates up to 72.2 Mbits/sec. The board can be polled every 10 msec using Modbus TCP commands as document in our Communications Boards user manual. Analog readings retrieved via WiFi can be updated 50 or 60 times per second, depending on the meter's 50 Hz or 60 Hz AC line noise rejection setting.

Cached operation is a key feature of the DPM-OPT-WXU board. That board polls its host meter at the maximum rate allowed by the meter's main board, and it can in turn be polled asynchronously as a Modbus slave at a much faster rate using WiFi, USB.

An external 2.4 GHz antenna with an antenna gain of 5 dBi is connected to the meter by a 30" (76 cm) low-loss RG174 cable. Use of an external antenna allows the meter to be installed in a metal cabinet and the top of the cabinet to serve as the ground plane for the antenna. Use of an external antenna increases signal strength by about 10 dB compared to that of the internal antenna used in our DPM-OPT-WU WiFi board. Note thal DPM-OPT-WU and DPM-OPT-WU equipped meters can be mixed in the same system.

A mini-USB connector is standard and can be used for meter programming or for data polling as a Modbus slave at 38400 baud in parallel with polling via WiFi. To connect to the USB port of a PC, use our cable CBL07 or another readily available A-male to Mini-B USB cable.

Setup of WiFi and USB communications uses our free Laurel Network Setup (LNS) utility. That software allows users to enter the WiFi system's SSID and password, which is then be stored in the WiFi board. It automatically discovers the board's IP address assigned by the WiFi router, the COM port used for USB communications, the meter type, and the signal conditioner type. LWIFI board setup and available Modbus commands are documented in our DPM-3 Serial Communication Manual Communications Boards user manual. The USB port can also be used with our free Instrument Setup (IS) software to set up the host instrument.

WiFi meter external antenna Operation

 DPM-3-OPT- board with antenna and antenna cable Network with a WiFi router and three meters with an LWIFIX WiFi interface


WiFi Operation

Included with LWIFIX WiFi board, external antenna, 30" antenna cable, USB 2.0 port
WiFi module ATWINC1510-MR210UB (for external antenna)
Connector to antenna Hirose male U.FL
Antenna cable 50 ohm RG174, 76 cm (30") long
Cable loss at 2.4 GHz 2 dB
Cable connectors Female U.FL to circuit board, RP-SMA to antenna
Antenna External omnidrectional 2.4 GHz dipole
Antenna polarization Vertical
Antenna gain 5 dBi
Antenna height 200 mm (8")
Antenna location Top horizontal surface of metal cabinet
Wireless LAN standard IEEE 802.11 b/g/n
Transmit/receive frequency 2.4 GHz license-free ISM band
Maximum data rate 72.2 Mbits/sec, MCS index 7, with 802.11 n
Maximum radio range 90 m (300 ft) unobstructed outdoors

USB Operation

USB applications Our Network Setup, host meter programming, or operation of host meter as a Modbus slave.
USB connector Mini-USB Type B jack
USB cable Mini-USB Type B to USB Type A (ACA-USBA/MB)
USB data rate 38400 baud
COM port Discovered by Network Setup (LNS) utility

Cache Operation

Data written into cache Display value or set of 6 values (user selectable)
6 values for analog in DPMs Alarm status, display value, peak, valley, display value, display value
6 values for scale meters Alarm status, display value, peak, net weight, gross weight, display value
6 values for counters Alarm status, item 1 (display value), peak, valley, item 2, item 3
Write interval for 1 value 16.666 mecs or 20.000 msec (filtering set for 60 Hz or 50 Hz noise rejection)
Write interval for 6 values 100 msec or 120 msec (filtering set for 60 Hz or 50 Hz noise rejection)
Read inteval from cache Set by external Modbus Master, 10 msec minimum

Measurement Update Intervals

Analog input meter 16.666 msec or 20.000 msec (filtering set for 60 Hz or 50 Hz noise rejection)
Totalized pulse readings Signal period or gate time from 10 msec to 199.99 sec
Frequency/rate readings Gate time + 30 msec + 1-2 signal periods

Communication Protocols

Data I/O via WiFi Modbus TCP/IP (same command set as Modbus RTU)
Data I/O via USB or RS485 Modbus RTU
Meter programming Front panel keypad or Instrument Setup (IS) software


Board dimensions 79 x 39 mm
Mounting location Middle slot of the DPM-3 digital panel meter


Operating temperature -40°C to 85°C
Relative humidity 95% from 0°C to 85°C, non-condensing
DPM-OPT-WXU N/A 200.00