SECTION 27. PROTOCOL CONVERTERS
27.1 DESCRIPTION
RFL 9300 Protocol Converters provide standard communications over the Modbus RTU and DNP based substa-
tion networks. The converters come in a variety of physical and software variations to suit different applications.
The most common application is with a 2 terminal 93B relay with a single communications path. In this applica-
tion, the converter is installed in the unused communications adapter slot and is wired to the 9300 relay I/O via
an internal cable. This cable brings the RS232 signals that used to go to the rear DB9 connector to the con-
verter. This allows the converter to communicate directly with the 9300 as if it were attached to the rear comms
port.
The converter interrogates the 9300 and maps the responses into variables conforming to one of two specifica-
tions. Both Modbus and DNP 3.0 are supported. With the appropriate interrogation software the user can get
the settings, measured values, and sequence of events data from the relay.
Due to security concerns, RFL has elected not to make settings changeable via the external protocols. These
protocols are networked with unknown devices and contain little error checking and no security provisions. In
order to make setting changes one must use the front panel keypad or the RS232 port.
27.2 CONFIGURATIONS
The converters are available as two different hardware versions to support operation with an RS232 selector
board and without. The typical application does not use the RS232 selector.
The software is available in Modbus RTU and DNP versions. The Modbus is available only for 2 terminal sys-
tems. The DNP version is available for 2 and 3 terminal systems.
Table 27-1 lists the versions currently available: Special versions may be available. Contact RFL for more infor-
mation.
Table 27-1. Protocol Converters currently available
Part Number Protocol Terminals RS232 Selector Application
106785-1-1 DNP 3.0 2 No 93B
106785-1-2 DNP 3.0 3 No 93B
106785-1-3 DNP 3.0 2 No 93A
106785-1-4 Modbus 2 No 93B
106785-1-5 Modbus 2 No 93A
106785-3-1 DNP 3.0 2 Yes 93B
RFL 9300 RFL Electronics Inc.
October 20, 2004 27 - 1 (973) 334-3100
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