ALERT 2 Data Transmitters
The HSE ALERT2 Data Transmitter – Model 3306-02 is a powerful and flexible addition to HSE’s ALERT/IFLOWS family of products designed with the field technician in mind. The ALERT2 Data Transmitter is housed in a 17.8 cm (7 inch) diameter aluminum canister for use in ALERT/IFLOWS standpipe applications. The ALERT2 Data Transmitter’s standard configuration accepts up to 6 Analog inputs (plus internal battery), up to 2 shaft encoders, up to 2 precipitation, 2 SDI-12, wind speed, wind direction, and peak gust. Sensor connections to ALERT2 Data Transmitters are made via MS connectors. Unlike the ALERT/IFLOWS Transmitter – Model 3306-00 the ALERT2 Data Transmitter uses the ALERT2 reporting format through the addition of an ALERT2 modulator board and GPS receiver.
ALERT2 is the next generation data format for Hydological and Meteorological Data Collection Systems. Utilizing faster baud rates for transmission, more data can be sent in shorter messages. This increase in data capacity allows the ALERT2 Data Transmitter to transmit field data in calibrated, floating point engineering units, and also provides a tremendous increase in the number of available Station IDs. Another significant advancement offered by ALERT2, is the ability to assign TDMA time slots to each ALERT2 Data Transmitter in the system which enables exceptional system data throughput even during extreme weather events. This report scheduling capability is possible due to the precise timekeeping enabled by the ALERT2 Data Transmitter’s on board GPS Receiver. The increased message capacity of ALERT2 Data Transmitters also allows for the inclusion of Forward Error Correction that has been demonstrated to overcome any loss of throughput due to bit errors that can result from the higher transmission baud rates.
Upgrading from ALERT to ALERT2
From its inception, the development of ALERT2 has included a transition path that would allow an existing ALERT system to migrate over time to ALERT2. The initial step requires the upgrade of the system’s Base Station Software to an ALERT2 compliant version and to replace the decoder and network repeaters to ALERT2 compliant models. ALERT2 Repeaters are capable of receiving data from both ALERT and ALERT2 format transmitters. Any ALERT messages received are converted to ALERT2 for re-transmission. These dual protocol repeaters allow a System Manager to replace gauge transmitters with ALERT2 Data Transmitters over time, as needed and as budget allows.
Programming ALERT2 Data Transmitter
The ALERT2 Data Transmitter’s basic programming mode allows you to configure the unit simply by using rotary switches. Four switches are used to set the ALERT2 Data Transmitter’s Station ID number and a fifth is used to select from factory-defined or user-defined preset sensor configurations for different station types. This allows for very quick set-up of the ALERT2 Data Transmitter without the need for a laptop computer in the field.
Alternatively, you can use the Insight Software (a graphical user interface; GUI) offered by HSE for fast, easy set-up from either a desktop or laptop computer in the field. This software is also used to program the ALERT/IFLOWS Transmitter – Model 3306-00 and to indicate the data transmitter is using the ALERT2 format there is a box to check on the opening page indicating the transmitter being programmed is an ALERT2 unit. By checking this box, the additional programming options such as TDMA Timing features become available. You can program the following parameters independently into the ALERT2 Data Transmitter for each sensor to be logged: Sensor name, sensor type, ALERT2 ID number, adder (offset) and multiplier, sample interval, reporting (transmission) interval, logging interval, hold off time, and log on transmission. Other sensor specific parameters can be programmed into the ALERT2 Data Transmitter for each sensor depending on the type of sensor. Each ALERT2 Data Transmitter enabled sensor can be programmed to transmit on a user Timed-defined basis and/or on a user defined amount of change, also known as Event Mode. Each ALERT2 Data Transmitter enabled sensor can log data on a user-defined time interval and can also be set to log data on Transmission.
ALERT2 Data Transmitter data is logged on a Secured Data (SD) memory card and can be retrieved via the USB or serial port. The ALERT2 Data Transmitter’s SD memory card can also be removed for later downloading and replaced with a spare card. The ALERT2 Data Transmitter is supplied with a 16 Gigabyte SD card.
The ALERT2 Data Transmitter can communicate via ALERT2 and SDI-12 Version 1.3 formats. While the ALERT2 Data Transmitter is supplied with a VHF or UHF data radio for ALERT2 data transmission, other communication devices such as GPRS radio or CDMA (cellular) can utilize the serial port. The ALERT2 Data Transmitter reports/transmits based on the reporting interval set for each sensor. There is a minimum 20 second standard hold off time after an initial radio transmission by the ALERT2 Data Transmitter before a second radio transmission will occur. The ALERT2 Data Transmitter’s hold off time may be increased. In addition to the standard hold off the ALERT2 Data Transmitter features a low battery hold off that disables radio transmissions when the battery drops below 10.5 V. The ALERT2 Data Transmitter will continue data logging even if transmissions stop due to low battery as long as the battery has power to power the transmitter. An override feature allows the ALERT2 Data Transmitter to report if the override value has been exceeded even if a transmission is not scheduled. The ALERT2 Data Transmitter can also act as an ALERT/IFLOWS repeater. If the ALERT2 Data Transmitter’s repeater mode is used the extra power consumption required for the receiver must be taken into account with your system design.
The ALERT2 Data Transmitter internal firmware is upgradable in the field. Latest firmware versions for the ALERT2 Data Transmitter are available to download under the Support tab for this product. The ALERT2 Data Transmitter firmware versions are downloadable via the USB cable. The ALERT2 Data Transmitter firmware download process will take just a few seconds.
Additional ALERT2 Data Transmitter features include fuse protection on solar input, battery and 12V switched to avoid damage to the unit through shorting (these fuses automatically reset when they cool off). Reversing the ALERT2 Data Transmitter’s battery terminals will cause no damage. The ALERT2 Data Transmitter offers a dedicated USB port for programming, data retrieval, and uploading of new firmware versions.