2.0 GENERAL INFORMATION
Thank you for your purchase of this Patton Electronics product.
This product has been thoroughly inspected and tested and is
warranted for One Year parts and labor. If any questions or problems
arise during installation or use of this product, please do not hesitate to
contact Patton Electronics Technical Support at (301) 975-1007.
2.1 FEATURES
• Operates asynchronously, point to point or multipoint,
over 2 or 4 wires
• Up to 50 multipoint device drops in a polling environment
• Data rates to 115.2 Kbps
• Passes transmit & receive data, one control signal each direction
• No AC power or batteries are required
• Variable high/low impedance settings
• Able to operate with or without “echo”
• Carrier can be set as “constantly on” or “controlled by RTS”
• Compact size ( 2.66” x 2.10” x 0.73”)
• Twisted pair connection via strain relief, RJ-11 or RJ-45
• Silicon Avalanche Diode surge protection
2.2 DESCRIPTION
The Model 2085 High Speed RS-232 to RS-485 Interface
Converter
provides exceptional versatility in a compact package.
Requiring no AC power or batteries for operation, the Model 2085
supports asynchronous RS-232 data rates to 115.2 Kbps over one or
two unconditioned twisted pair.
The Model 2085 passes one control signal in each direction and
can handle up to 50 terminal drops in a multipoint polling environment.
The Model 2085 may be configured for high or low impedance
operation, carrier may be set to “constantly on” or “controlled by RTS”,
and the unit can operate with or without “echo”. RTS/CTS delay may
be set for “no delay” or 8 mS.
The Model 2085 is equipped with either male or female DB-25 for
RS-232 connection. Options for twisted pair connection include
terminal blocks with strain relief, RJ-11, RJ-45 and DB-25 male or
female. Silicon Avalanche Diodes provide 600 watts per wire of
protection against harmful data line transient surges.
3
2085 SIGNAL
RS-485 SIGNAL
XMT+ ....................................+
XMT- .....................................-
The above wiring pattern applies regardless of whether you are
making the RS-485 connection via DB-25, RJ-11, RJ-45 or terminal
blocks. For specific wiring instructions, please refer to the previous
pages of Section 4.
4.2 WIRING FOR MULTIPOINT CIRCUITS
The Model 2085 supports multi-point applications using either a
star or daisy chain topology. Both topologies require special wiring, as
well as specific DIP switch settings for master and slave units.
Note:
Refer to
Section 3.2.2
for multipoint DIP switch settings.
4.2.1 STAR TOPOLOGY
Using a star topology, you may connect several Model 2085s
together in a master/slave arrangement. Maximum distance between
the units will vary based upon the number of drops, data rate, wire
gauge, etc. Call Technical Support for specific distance estimates.
Figure 7 (below) shows how to wire the two-pair cables properly for
a Model 2085 star topology. Note that the ground connection is not
needed.
14
HOST
FIRST SLAVE
SECOND SLAVE
XMT+
RCV+
RCV+
XMT-
RCV-
RCV-
RCV+
XMT+
XMT+
RCV-
XMT-
XMT-
Figure 7.
Star wiring for Model 2085 host and slaves
