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”
• Ultra-miniature size (2.50" x 1.20" x 0.75")
• Twisted pair connection via strain relief, RJ-11 or RJ-45
• Silicon Avalanche Diode surge protection
2.2 DESCRIPTION
The Model 2089 EIA/TIA-574 to RS-485
interface converter
provides exceptional versatility in an ultra-miniature package.
Requiring no AC power or batteries for operation, the Model 2089
supports asynchronous communication up to 115.2 Kbps over one or
two unconditioned twisted pair. Distances up to 15.0 miles are
attainable at lower data rates (1.2 Kbps, 19 AWG twisted pair).
The Model 2089 can handle up to 50 terminal drops in a multipoint
polling environment. For RS-485 applications requiring hardware
handshaking, the Model 2089 passes one control signal in each
direction. The Model 2089 may be configured for high or low
impedance, 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.
Options for twisted pair connection include terminal blocks with
strain relief, RJ-11 or RJ-45. Silicon Avalanche Diodes provide 600
watts per wire of protection against harmful data line transient surges.
3
14
HOST
FIRST SLAVE
SECOND SLAVE
XMT+
RCV+
RCV+
XMT-
RCV-
RCV-
RCV+
XMT+
XMT+
RCV-
XMT-
XMT-
Figure 5.
Star wiring for Model 2089 host and slaves
