User Manual
Operation
RFI-9256 Radio Modem User Manual Page 31 of 96
The address of each repeater to dial through is prefixed before the address of the destination radio and
extension. Thus to dial the auxiliary port of the radio with address 2200 first through repeater 10 and then
through repeater 43 the following dial string would be used:
ATD1043220001<CR>
In order to access the repeater slave’s terminal menu, dial up the menu system as if it were any other slave.
In order to access the repeater master’s terminal menu dial up the main port of the slave (the port that has
been connected through to the master unit), then use the master units AT command interface to bring up the
menu system via the
AT?
command.
When using back-to-back repeaters in dial-up networks, there are a number of rules that must be observed:
The escape character on the repeater master and repeater slave must be set to ‘-‘.
The escape guard time on the repeater master and repeater slave must be set to 200ms.
The main port DTR mode on both the repeater master and repeater slave must be set to “Hang-up
on DTR dropped”.
The local address of the repeater slave and repeater master must both be the same, and must both
be in the range 10-99.
The local address of all non-repeater units must be in the range 1000-9999.
The DTR line is used in the back-to-back repeater wiring harness in order to propagate Hayes hang-up
requests through the network. If this line is not connected there is a possibility that the hang-up request could
get lost and the repeater network lock-up, believing there to be an established connection.
For this reason it is not advised to use dial-up networking through back-to-back repeaters on the auxiliary
port.
4.3.4 SCADA Protocols
The RFI-9256 supports SCADA protocol networks in two ways:
Providing a point-to-multipoint broadcast network, where any SCADA packet that is inserted at
the master will be delivered to all slaves, and a SCADA packet inserted into any slave is delivered
to the master. This was covered in section 4.3.2.
Providing a point-to-multipoint routing network, where master to slave communications is no
longer broadcast. In this case the RFI-9256 will decode each SCADA protocol packet to extract
the destination address and match it against a radio address.
Routing services are provided for a number of SCADA protocols, specifically:
Modbus
Honeywell
DNP3