Xylem H-424MS V1.0 - Manual (Page 12)

1-4 Operation
H-424MS
The H-424MS modules comes from the factory with the following settings:
SDI Address: 0
Wakeup Interval: 15 Seconds
Inactivity Timer: 30 Seconds
These settings should work for most applications, these values provide a good compromise
between low power operation and system responsiveness. Both Master and Slave H-424MS
modules must be programmed with the SAME timer settings. The programmed timer settings of
the Master module can be observed or changed with extended commands addressed to sensor “0"
(see Chapter 2 for details). The settings of the remote (slave) module cannot be accessed
remotely. To observe or change the timer settings of a remote module the module must be
temporarily removed from service, jumpered as a master, and connected directly to the data
recorder as a local “sensor”. After programming, the module must be jumpered as a slave again
and returned to service at the remote site.
1.6 Connecting The Antenna
The H-424MS may be used with a 50-ohm, 900 Mhz antenna providing the effective radiated
power is 6dB or less. The antenna connector is a reverse type-TNC connector which is required
to meet FCC part 15.203 regulations. A simple vertical whip antenna will work up to 2 or 3
miles. Longer distances require a directional antenna with gain. A 6dB or 9dB YAGI will work
fine, do not use a 12dB model. At 900 MHz, RG58 type coaxial antenna feed lines have
excessive loss (1.8dB/10 feet). Consider using newer low loss RF cable such as Times
Microwave LMR-400 or similar (0.8dB/10 feet). The LMR-400 requires special RG8
connectors.
The H-424MS is packaged in a weather tight enclosure and is best mounted as close to the
antenna as possible. The H-424MS has a ground lug which should be connected to a good earth
ground with a heavy copper wire. The ground helps provides lightning protection for the radio,
your sensors and the data logger.
The H-424MS radios all operate at the same frequency. If multiple data logger sites are deployed,
make certain the radios of each separate logging site cannot “hear” each other. The radios can be
ordered with alternate frequencies, please contact the factory for further information.