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
• Conforms to EIA RS-422 Standard
• Bi-directional data conversion
• Data Rates to 19.2 Kbps over two twisted pair
• No AC power required–draws operating power from RS-232 signals
• Passes transmit and receive data–handshaking lines looped back
• Convenient thumb screws on DB-9 (female) interface
• Ultra-miniature size (2.50" x 1.20" x 0.75")
• Twisted pair connection via strain relief, RJ-11 or RJ-45
• Made in the USA
2.2 DESCRIPTION
The Patton Model 222N9 RS-232 (EIA-574) to RS-422 interface
converter allows asynchronous PCs, terminals and laptops employing
the EIA-574 (RS-232/ DB-9) interface to communicate with devices
using RS-422 balanced electrical signals. Facilitating bi-directional
data conversion over two twisted pair, the Model 222N9 draws all
necessary operating power from data and control voltages on the EIA-
574 interface. The Model 222N9 supports data rates to 19.2 Kbps and
distances to 4000 feet. All control signals are looped back at the EIA-
574 interface.
The Model 222N9 is housed in an ultra-miniature ABS plastic
enclosure measuring 2.5”L x 1.2” H x .75” W. Options for twisted pair
connection on the RS-422 side include terminal block with strain relief,
RJ-11 and RJ-45. The EIA-574 side is available with a choice of male
or female DB-9 connector.
The surge protected Model 222N9S uses high speed avalanche
diodes to intercept data line transient surges and shunt them safely to
chassis ground. Compliant with IEC 801.5 level 2, 1kV, the 222N9S
can protect itself and connected equipment from nearby lightning
strikes, and other surges of electromagnetic radiation.
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3.0 INSTALLATION
The Model 222N9 is easy to install and requires no pre-
configuration. This section tells you how to properly connect the Model
222N9 to the RS-422 (twisted pair) and EIA-574 (DB-9) interfaces, and
how to operate the Model 222N9.
3.1 CONNECTION TO THE RS-422 INTERFACE
The Model 222N9 supports data-only communication distances up
to 4000 feet between itself and the RS-422 device. To function
properly, the Model 222N9
must
have two twisted pairs of metallic wire.
These pairs must be dry, unconditioned metallic wire, between 19 and
26 AWG (the higher number gauges may limit distance somewhat).
For your convenience, the Model 222N9 is available with several
different physical interfaces on the RS-422 side: RJ-11 jack, RJ-45
jack, and terminal blocks with strain relief.
3.1.1 TWISTED PAIR CONNECTION USING RJ-11 OR RJ-45
The RJ-11 and RJ-45 connectors on the Model 222N9's twisted pair
interface are pre-wired for a standard TELCO wiring environment. The
signal/pin relationships are shown below:
RJ-1
1 SIGNAL RJ-45 SIGNAL
1----------------GND* 1 --------------N/C
2----------------RCV- 2 --------------GND*
3----------------XMT+ 3 --------------RCV-
4----------------XMT- 4 --------------XMT+
5----------------RCV+ 5 --------------XMT-
6----------------GND* 6 --------------RCV+
7 --------------GND*
8 --------------N/C
* Connection to Ground is Optional
When connecting two Model 222N9s it is necessary to use a "cross
over" cable. The diagram below shows how a cross over cable should
be constructed for an environment where both Model 222N9s use a 6-
wire RJ-11 connector. Similar logic should be followed when using RJ-
45 connectors or a combination of the two.
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