The ACR-LGW device represents the universal LoRaWAN Gateway combining wireless Wi-Fi, LoRa and LTE interfaces with the metallic ETHERNET interface and USB connectivity. Three possible power supplying methods can be easily selected including the PoE according to 802.3af standard.
ACR-LGW is a compact, single-box device manufactured in two mechanical versions. Both versions satisfy the Ingress Protection IP67, cables run via waterproof grommets.
Depending on customer requirements, the PoE injector or the power supply can be delivered together with the ACR-LGW device.
The ACR-LGW meets all demands to become the heard of the up-to-date and general-purpose network of IoT end devices.
|Power supply options|
|Power consumption:||Max. 4 W (no LTE), 7W (with LTE)|
|Regulated DC power input|
|Voltage:||5 V DC|
|Voltage:||24 V … 50 V DC|
|Voltage:||24 V … 50 V DC|
|Auxiliary DC power supply|
|Voltage:||12 V … 50 V DC|
|Cable:||100 Mbps ETHERNET (100BASE-TX)|
|Wireless:||802.11 b/g/n 2.4 GHz, Dual-mode|
|Wireless:||LTE-TDD/LTE-FDD/HSPA+/GSM/GPRS/EDGE, microSIM holder|
|Wireless:||LoRa EU868, US915|
|USB:||USB 2.0 (USB Type A connector)|
|Console:||USB 2.0 (control and service interface)|
|Console:||UART (control and service interface, 115200 Bauds)|
|Max. output power:||27 dBm|
|Sensitivity:||-141 dBm @ 300 bps|
|LoRaWAN uplink:||8 normal multi-SF channels (SF7 to SF12, 125 kHz), 1 single SF high speed data rate channel and 1 GFSK channel|
|LoRaWAN downlink:||1 normal channel (125 kHz, 250 kHz, 500 kHz LoRa configurable or GFSK)|
|Communication data rate:||292 bps … 50 kbps|
|LoRaWAN class:||A; B; C|
|LoRaWAN antenna gain:||3 dBi default (upon request can be changed for higher gain antenna)|
|Operating frequency bands:||EU 863-870MhZ (different frequency bands upon request)|
|SoC:||580 MHz MIPS24KEc|
|Memory:||128 MB DDR2 RAM, 32 MB onboard Flash|
|OpenWRT 18.06 operating system|
|LuCi Web interface for configuration|
|SSH Console for configuration|
|Dimensions:||240 x 190 x 90 mm|
|Operational temperature:||-30 °C to +60 °C|
|Mounting:||Wall / Pole|
|Firware update:||Over the air (OTA)|
Three different options can be selected to power the ACR-LGW device. Two options are recommended from the manufacturer with regards to prefabricated cables availability and easy installation. Based on specific model, the recommended power supply will be delivered together with the ACR-LGW.
One of the most recommended power supply solutions for ACR-LGW is via PoE. Active PoE according to 802.3af and passive PoE are supported.
The offered option of the active PoE injector complies with the 802.3af standard and provides 48 V DC and 0.5 A DC, thus the power of 24 W gives enough margin for ARC-LGW device.
The ACR-LGW device needs to be configured to the PoE power option.
|Input voltage||90 – 240 V AC|
|Output voltage||48 V DC|
|Output current||max 0.5 A DC|
|Output power||max 24 W|
The PoE injector is delivered with the standard power cable terminated with IEC-320 C6 and CEE7/7 plugs.
The second recommended power supply option for the ACR-LGW device includes the regulated DC power supply with 24 V DC level delivering 19 W of power.
The ACR-LGW device needs to be configured to the DC power supply option.
|Input voltage||100 – 240 V AC|
|Output voltage||24 V DC|
|Output current||max 0.8 A DC|
|Output power||max 19 W|
The output connector from the power supply is replaced with cable pins to enable the connection with the ACR-LGW device.
The customer can utilize already established electrical distribution of low-level DC voltage and supply the ACR-LGW from it.
It is possible to supply the ACR-LGW device from the regulated DC power supply with stabilized and well filtered 5 V output providing at least 3 A DC current.
The other power option is the DC voltage in the range 11 – 50 V DC. This power supply must be capable to deliver the power at least 15 W. The low DC voltage threshold depends on the cable length. The voltage drop over the power supply cable is proportional to its length.
The ACR-LGW device needs to be configured to the customer based power supply option. Always consult power options with the supplier or manufacturer to reach the best result.
|3 dBi antenna - default|
|Mounting:||Wall or pole|
|6 dBi antenna - optional|
*For variant with LTE
The internal electronics of ACR-LGW is assembled on a single PCB. All interfaces are realized by connectors and screw terminals that are making the installation very easy.
The power section is able to work with three different power supply inputs. Based on customer requirements, the ACR-LGW can be powered from the regulated, stabilized and well filtered DC power supply providing the voltage level 5 V DC with a minimum 3 A DC current. The other option is general power supply input for a broad voltage range 11 V – 50 V DC, fulfilling the power consumption 15 W. The ACR-LWG can also be configured for Power-over-ETHERNET (PoE), fulfilling the power consumption 15 W. Both versions, passive PoE as well as active PoE according to an 802.3af standard, are supported.
The core of ACR-LGW is based on a single board IoT computer with MIPS32 24Kc CPU and 580 MHz clocks. The computer is equipped with 128 MB RAM and 32 MB Flash memories. The microSD card module enables the user to expand the storage capacity.
The single-board computer contains the metallic ETHERNET interface for a maximum of 1 Gbps data rate (1000BASE-T). Finally, lower data rate 100 Mbps is led to ACR-LGW RJ-45 connector.
The assembled dual-mode wireless interface 802.11b/g/n for 2.4 GHz band enables us to run the Wi-Fi AP as well as the WiFi client as the same time. Thus it can create a bridge between wireless and metallic networks.
The core part is also equipped with other interfaces (e. g. UART, USB, I2C, SPI) to connect to internal components and functional blocks.
The LTE functionality is provided via the multi-band SIMCom module which can be configured for B1, B78, B3 B7. B8 or B20 bands. The compatibility for GSM/GPRS/EDGE services in 900 MHz and 1800 MHz bands is assured. The MicroSIM slot is assembled on the TOP of the PCB for the user SIM card.
ACR-LGW is equipped with full featured LoRa transceiver based on HW solution from the SEMTECH Company. The LoRa radio part is capable to output up to +27 dBm power to completely satisfy specifications for the sub-band G3. To fulfill requirements for other sub-bands, the output power is regulated.
The USB 2.0 enables to connect any USB device (e.g. the mass storage unit, keyboard) via the USB type A connector. The USB port is capable to power supply regular USB mass storage devices and is protected with a over-voltage and over-current circuity.
UART port provides a console interface and serves for the service and diagnostic purposes. UART RX/TX signals are referenced to 3.3 V level. The default rate is 115200 Bauds. The second diagnostic possibility is available through the miniUSB port. The USB signal is converted to the UART interface with identical parameters.
The ACR-LGW PCB is assembled with almost all components from the bottom side. The top side contains interfaces and connectors to make the installation and connections more easier without the need to completely remove the PCB from the box.
Not all connectors need to be assembled on the PCB. It depends on custom requirements.
The next figure represents the full functionality of the ACR-LGW. Not assembled connectors and components are used for debugging purposes or will serve for future functionalities.
All antennas are connected via MCX connectors. To disconnect the antenna, gently pull the connector in the direction from the PCB until it releases. To connect the antenna, gently push the connector towards the PCB until it clicks.
The power supply is connected via the screw terminals. Properly tight screws in terminals to avoid transition resistance and possible supply cuts.
For service operations, settings and control, two console service connectors can be used. The default rate is 115200 Bauds.
The UART serial interface uses RX and TX signals only. Voltage levels are referenced to 3.3 V DC. The second console interface is converted from UART to USB and guided out on the miniUSB connector.
The user can utilize four digital general purpose input/output ports directly connected to the core module. Also the 3.3 V DC voltage is accessible on the pin header SV2, that is assembled based on user requirements.
These general purpose input/output ports can be utilized to sense or control another hardware unit assembled together with the ACR-LGW device inside the metallic box.
All interfaces are equipped with ESD protection devices. Used components secure sufficient level of isolation between an external power supply and internal electronics.
The OpenWRT operating system is running on the single board computer and is responsible for the control of the whole ACR-LGW unit. The OpenWRT is installed on the Flash memory and it contains modification and add-ons directly prepared for the ACR-LGW device hardware.
The newest and stable version is always installed on the new device and all necessary settings are done during the manufacturing process to fulfill customer requirements.
If necessary, the procedure for the OpenWRT operating system installation can be found under the link. The whole procedure is not simple and requires advanced skills. The correct source code for the particular hardware needs to be selected and built. Please contact the supplier/manufacturer to discuss the operating system installation.
The procedure describing the update of the operating system from the LuCi web interface can be found in documentation accessible under the following link.
The correct source file containing the operating system is required prior the installation. The procedure is not simple and requires some skills. Please contact the manufacturer/supplier to discuss the update options.
The other method for the operating system update utilizes the ETHERNET connection and SSH source image transfer to the destination ACR-LGW device. The update is run directly from the ACR-LGW device.
Contact the supplier/manufacturer to obtain the correct and fresh source image with the operating system and follow instructions from the section SSH system update.
The new operating system version can also be installed from the USB memory device. This method is especially useful, when the ACR-LGW device update is not possible using previously mentioned procedures (e.g. the ACR-LGW device is not responding to a terminal connection or is not able to connect via the ETHERNET).
Contact the supplier/manufacturer to obtain the correct and fresh source image with the operating system and follow instructions from the section USB system update.
The ACR-LGW device is already configured according to user requirements from the manufacturing process. Do not make configuration changes, if you are not absolutely sure, what these changes affect. It is recommended to contact the supplier or manufacturer and consult the intended issue.
The ACR-LGW can be user configured via two channels. One way of configuration is via SSH communication protocol using commands sent through the terminal application. The other way how to configure the device is via the GUI using LuCi web interface its package is installed in OpenWRT operating system.
Before attempting any of the following operations, assure the ETHERNET connection and turn on the power supply for the ACR-LGW device.
Screenshots displayed in the following sections correspond to recommended, default settings, if not specified otherwise.
For both configuration options, the user connects to the device via the ETHERNET interface, and the IP address is required.
Detailed information about getting the IP address is located in the section IP Address Discovery.
The device running on the OpenWRT always listens for SSH commands on the port 22. To connect via the SSH, type the command:
Where xxx.xxx.xxx.xxx is the discovered ACR-LGW IP address, example “192.168.20.148”, see section IP Address Discovery.
To control and configure the ACR-LGW device via the SSH connection, visit the OpenWRT web page and follow the online documentation and the User Guide under the link.
To close the SSH session, use the command: