Preliminary Release
Alligator Communications Model 2788 Technical Manual REV2.3 Copyright © 2019
Page 15
3.0 Field Configuration and Verification
Prior to field installation of the 2788, it is crucial that that bench configuration and testing be
done using cables and RF attenuators to duplicate the deployed system or subsystem. This adds
confidence that the configuration has been done properly and stream-lines field installation.
Each remote configured 2788 must be tested with a master configured 2788 to verify proper
operation. This places deployed radios in final configuration so no additional programming is
necessary when final field installation is performed. This is highly recommended for a smooth
system deployment.
3.1 Field Configuration Bench Test
1.
Update the 2788 IP address to the desired fielded IP address. Each 2788 must be
assigned to a unique IP address in the subnet of the access point router. For example,
ip=10.0.0.5<CR>. Once this instruction is entered, the Telnet connection is lost and must
be re-established on the new IP address.
2.
Re-establish Telnet communications on the new IP address. Typically use a second lap-
top with its IP address configured to the desired IP subnet range and with a copy of
puTTY that can start a Telnet session with the 2788 on the newly assigned IP address.
3.
Assign the access point router gateway IP address. For example, gw=10.0.0.1<CR>.
4.
Assign the subnet mask. For example, sm=255.255.255.0 .
5.
If desired, assign a different Telnet port from the default port 23. For example,
tnp=50000<CR>. If you change the Telnet port, you lose the session and must reconnect
on the newly assigned port number with puTTY.
6.
Assign a group code if desired to identify a unique group of radios. This blocks accidental
communications with other 2788 radios. For example, gc=3<CR>.
7.
Decide if the 2788 is a master or remote. There is only one master 2788 radio in a point-
to-point or point-to-multipoint radio network. For a master, configure with the
command om=1<CR>. For a remote, configure with the command om=0<CR>. The
primary difference between a master and remote is that a master passes host polls and
other unsolicited messages. The remote radio passes responses from the polled RTU.
Occasionally the RTU generates unsolicited transmissions to the remote radio. This
causes no disturbance to the polling process. The remote radio buffers the packet(s)
until a clear time to send back to the host. Note that both the master radio and remote
radios are transparent to the protocols encapsulated in the Ethernet packets or RS-232
serial data.
8.
If using RS-232, select the terminal data rate. The data rate can be selected from 1200,
2400, 4800, 9600, or 19200 bps. For example, dr=9600<CR> selects 9600 bps. Note that
in RS-232 systems, the Ethernet connector is still used for Telnet control of the 2788.
The 2788 can handle RS-232 and Ethernet concurrently.
9.
The 2788 has various forwarding modes to limit Ethernet access to the radio network at
both the master and remotes ends of the radio link. This aids in preventing flooding the
radio network with unwanted packets. The 2788 shipping default is fm=3<CR>. This
