Monnit devices are offered in two generations. The ALTA line and the Commercial line operate with different radio hardware. The first generation products were developed by Monnit prior to the release of ALTA. There are unique characteristics and behaviors which means they are not cross-compatible. This article will outline the differences between the two generations and unique features of the ALTA line.
Identifying the generation of a device
When physically examining the hardware, the ALTA line will have a white and blue label marked with the ALTA label. Both devices come in the same Coincell, AA, and Industrial enclosures, but Commercial devices will generally have a black label marked with “Monnit” in white letters and/or a colored label.
ALTA (Second Generation) Wireless Sensor Label
Monnit (First Generation) Wireless Sensor Label
Looking up the generation type
If you are unsure of the generation of your device, you can use the tool at the following link to determine which generation to which your device belongs. ALTA Devices will list the word “ALTA” in the Radio Band field. You will need the sensor ID and Security Code to perform the lookup.
Reviewing the Part #
The part number also identifies the generation. ALTA parts include the number “2” in the part number following MNS or MNG. For example, the Part # for a temperature sensor would be “MNS2-9-W2-TS-ST” for an ALTA 900 MHz Temperature Sensor, and “MNS-9-W2-TS-ST” for a Commercial (Generation 1) Temperature Sensor.
Differences in radio technology
There is a fundamental difference in the radio technology with which each generation operates. While the Commercial devices transmit on a specific designated channel within the frequency range for that sensor, ALTA devices use Frequency Hopping Spread Spectrum (FHSS) technology. This increases the reliability and range of the radio communication. This difference is the primary reason ALTA devices do not communicate with Generation 1 devices.
As a result of the different RF technologies between Commercial and ALTA devices, the range of sensors to gateway differs. While Commercial sensors can communicate with gateways 250 - 300 feet (75 - 100 meters), ALTA sensors can communicate with gateways 1,000 - 1,300 feet (300 - 400 meters) away through 10 to 13 walls.
Differences when sensors first connect to gateways
When Commercial sensors first connect to a gateway, the gateway transmits the readings from this transmission on the gateway’s subsequent heartbeat. This means that when a sensor is first powered up and communicates with a gateway, you will need to wait until the gateway’s subsequent heartbeat to see the data in the Monnit software.
When ALTA sensors first communicate with a gateway, these transmissions are recognized by the gateway, and transmitted immediately by the gateway to the server. This means that when you first power on an ALTA sensors, the software displays those readings prior to the gateway’s next scheduled heartbeat. This means that when you are first setting sensors up, you will notice that data from ALTA sensors appears in the software more quickly than Commercial sensors.
When an ALTA sensor first communicates, you will see 4 or 10 transmissions, 30 seconds apart. This is a result of the sensor completing its initial start up test and handshake with the gateway. This is generally referred to as the sensor “Joining” the gateway. After the initial handshake, the sensor will begin to check in on the scheduled heartbeat.
Differences in Link Mode
When a sensor loses connection to a gateway, the sensor enters Link Mode. Both Commercial and ALTA sensors offer Link Mode operation, however they differ in the manner in which Link Mode is executed. Once a Commercial sensor enters Link Mode, it attempts to seek out a gateway every 120 minutes.
When an ALTA sensor enters Link Mode, it attempts to seek out a gateway with a “cascading” approach. This is to say that after it loses connection to a gateway, the sensor attempts to seek out a gateway more frequently at first, and tapers off the number of attempts it makes to find a gateway. After losing connection, ALTA sensors scan for new gateways at 0 seconds, 5 seconds, 15 seconds, 30 seconds, 1 minute, 2 minutes, 3 minutes, 5 minutes, 15 minutes, and finally then default (1 hour). Once it hits 1 hour it will scan at the default interval repeatedly until it relinks to a gateway.
ALTA sensors offer logging in flash memory stored on the sensor, whereas Commercial sensors do not. This means that if your sensor loses connection to the gateway (for example, if the gateway loses power), ALTA sensors continue to take readings and log those readings in flash memory while the sensors are in Link Mode. When the sensor is able to reconnect to the gateway, these logged messages are subsequently uploaded to the gateway and transmitted to the Monnit server.
Most ALTA sensors store up to 512 readings in memory. Most recent versions of sensor firmware (14.x.x.x) store up to 3200 readings. Additionally, sensors running firmware 14.x.x.x and later have the ability to store readings even after being powered off for short periods. This means if the sensor loses connection with the gateway and subsequently the battery for the sensor is depleted, the readings logged prior to the battery depletion will be transmitted after power is restored to the sensor.
ALTA sensors offer 256 bit AES bank-grade Encrypt-RF™ encryption during transmission to and from the gateway. This means that radio transmission between ALTA sensors and gateways is completely secure, whereas the Commercial (Generation 1) devices do not offer encryption during radio transmission.
Many of the more recent sensors such as Water Puck, Vehicle Detect-Counter, Air Quality PM 2.5, CO2, Air Velocity, H2S, Propane Tank, and others are available only in the ALTA line. Other previous sensor offerings such as the Seat Occupancy, Compass, Flex, Liquid Level, and others are available only in the Commercial line. If you are interested in a sensor offering specific to the ALTA or Commercial line, consult your salesperson.
ALTA and Commercial (first generation) sensors also have differing support in various versions of Monnit software. For example, ALTA sensors are not supported in the legacy version of iMonnit Express (version 220.127.116.11 and earlier). For a list of sensors and software compatibility, you can visit the following link. There is a drop down menu toward the top left where you can select the generation type.
Software/Device Compatibility Comparison
Monnit revolutionized the IoT industry with its first generation Commercial line of sensors. Once again, Monnit has raised the bar with its ALTA brand of wireless devices. Our second generation products offer a sensor catalog and feature set which is the gold standard for IoT sensors. Feel free to contact Monnit Support with additional inquiries.