User Manual

MHX-2400 Operating Manual: Chapter 2 Initial Setup and Configuration 7
Warning: Using an antenna that
is inappropriate for use with the
MHX-2400 module could result in
undesired performance, and may
damage the unit. It is the user’s
responsibility to ensure the
antenna has adequate lightning
protection.
How to Set Up A Simple Network
The MHX-2400 will always be in one of two states:
n Data Mode – When in this state, the modem is listening and talking
to other modems in the network (the modem is online).
n Command Mode – When in this state, the modem is awaiting “AT
Commands” from the serial port. These commands are used to
configure all operating parameters of the modem. When in this
state, the modem is “offline”.
To implement the very basic network illustrated in Figure 2, Network 1,
n Plug the modem into the development board and connect a straight-
through serial cable between the development board and the
terminal (e.g., your PC)
n Connect an antenna cable and antenna to the module.
n Configure the unit to Factory Setting 1 by typing AT&F1 <return>.
This puts the unit into Master Point-to-Multipoint mode.
n Store these settings to memory by typing AT&W <return>.
n Put the modem into Data Mode by typing ATA <return>. There are
other ways to enter Data Mode, which are discussed in Chapter 3.
n Perform the above steps for the second unit, using the command
AT&F2 instead of AT&F1. This will configure the second unit as a
Slave.
The units should now be communicating. Remember, the parameters defined
by AT&F1 and AT&F2 will likely not be the most ideal for your application,
but will quickly allow you to test the units. A complete summary of the
settings defined by AT&F1,2,3 and 4 can be found in Appendix D. Factory
Default Settings.
Settings are not immediately stored in non-volatile memory, therefore, the
command &W is issued to store the current configuration into non-volatile
memory. Settings are retained even after powering down. All user selectable
parameters for the MHX-2400 are described in detail in Chapter 3:
Configuration Options.
2.4 Checking the Link
To check if the units are communicating, observe the LED indicators on the
development board. If the link is good, up to three RSSI outputs on the Slave
modem should be active; and if the link is absent (due to a fault at one end or
another, such as misconfiguration), the outputs will be in either “scanning
mode” or inactive.
Characters typed at the Master terminal should appear at the Slave’s terminal,
and vice versa. Also, verify that the RX LED blinks as packets of data are
received at the Master modem. As data is sent from Slave to Master, the RX
indicator should blink on as correct packets of data are received. It is
recommended that if MHX-2400 modules will be deployed in a field where
large distances separate the units, the modems should be configured and
tested in close proximity (e.g., in the same room) first to ensure a good link
can be established and settings are correct. This will facilitate
troubleshooting, should problems arise.