The Laureate WiFi and USBcommunication board P/N LWIFIX allows a Laureate 1/8 DIN digital panel meter, counter or timer 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. In addition to wireless operation, high data and polling rates are a major advantage compared to Laurel's first-generation communication boards.
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 Gen 2 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 LWIFIX 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 or RS485.
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 LWIFI WiFi board. Note thal LWIFI and LWIFIX 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 Gen 2 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 Operation | |
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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 | Laurel 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 (CBL07) |
USB data rate | 38400 baud |
COM port | Discovered by Laurel 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 proramming | Front panel keypad or Instrument Setup (IS) software |
Mechanical | |
Board dimensions | 79 x 39 mm |
Mounting location | Middle sloft of Laureate Series 2 panel meter or counter |
Environmental | |
Operating temperature | -40°C to 85°C |
Relative humidity | 95% from 0°C to 85°C, non-condensing |