Patton electronic IM 1/F user manual Features, Description Applications and Associated Timing

2.0 GENERAL INFORMATION

Thank you for your purchase of this Patton Electronics product. This product has been thoroughly inspected and tested and is warrant- ed for One Year parts and labor. If any questions or problems arise during installation or use of this product, please do not hesitate to con- tact us at: (301) 975-1007, http://www.patton.com; support@pat- ton.com.

2.1 FEATURES

•Designed for use with Patton Electronics Access products that receive QuickConnectTM Modules and support 64K or 128K syn- chronous rates.

•Provides 64K codirectional interface compliant with the G.703 electrical specs.

•Offers a single Tx/Rx interface with a standard RJ-45 connector as specified in TBR 14.

•Option to work in two timing modes: Clear channel or octet timing.

•Complies with ITU/CCITT G.823 (Control of Jitter).

•Point-to-point distance up to 4,000 feet (1219m) using 24 AWG twisted pair.

•Made in the U.S.A.

2.2 DESCRIPTION

2.3.1 APPLICATIONS AND ASSOCIATED TIMING

There are two typical applications that result in two different timing modes for the G.703 interface. These are illustrated below.

Timing of Application 1: Network Loop Extension

In this application, the network supplies the timing for the entire system. The first G.703 recovers the timing. It has to smooth the clock before it supplies the clock (XCLK1) and the data (TXD1) to the first modem transmitter, so it can directly use the clock. The Rx of the second modem recovers the clock and presents a “jittery” clock (RXCLK1) and data (RXD1) to the second G.703’s transmitter. This transmitter has to smooth the clock before it uses the clock to transmit.

The Rx of the second G.703 recovers the timing and clocks the data into a FIFO. The Tx of the second modem takes its recovered clock and sends it (TXCLK1) to the G.703 FIFO for data (TXD1). The Rx of the first modem recovers the timing and clocks (RXCLK1) the data (RXD1) into a FIFO. The Tx of the first G.703 uses the first G.703’s recovered clock and sends it to the FIFO for data.

G.703 INTF-	G.703 TX	HOST
	SMOOTHS	MODEM -
MODEM
	RX MODEM	RECOVERED
TIMED MODE
	CLOCK	TIMING

The Patton Model IM 1/F Interface Module converts data from a

64K G.703 network into a Transistor-Transistor Logic (TTL) compatible signal that is transported by the PE 1090 or 1092 Modem or a similar 2 or 4 wire short haul modem that has identical pin outs and edge con- nector style (see note, below). The G.703 network provides a 64K co-

RX

TX

G.703

TX

RX

FIFO

FIFO

RX

TX

directional three level signal using either octet timing or clear channel mode. The IM will detect and pass either octet timing (preserving byte integrity over a 128kbps modem link) or clear channel timing (without byte integrity preservation) over a 64Kbps modem link. The IM is

CSU DTE

SECOND MODEM

capable of handling either network timing or modem timing, thereby realizing network extension or network replacement configurations. Clock jitter is attenuated according to G.823.

2.3 SYSTEM DESCRIPTION

This section describes the features that the entire system (G.703 interface, combined with the modems) will support.

NOTE: The “smoothed” clocks referred to in this section indicate that a phase locked VCO is used to create a jitter free clock that is

RX

TX

NETWORK

TX FIFO RX

G.703
	RX		FIFO		TX
	SMOOTHED
		FIRST MODEM
G.703 INTF-				HOST
				MODEM -
NETWORK
				INTERFACE
TIMED MODE
				(EXTERNAL)
				TIMING

2 or 4 Wire

locked to a source clock.

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Figure 1. Network Loop Extension Configuration

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