RAD Data comm T1 - Manual (Page 17)

FOM-E1/T1 Installation and Operation Manual Chapter 1 Introduction
Functional Description 1-3
1.2 Physical Description
FOM-E1/T1 is a compact unit, intended for installation on desktops or shelves. An
optional rack-mount adapter kit enables FOM-E1/T1 installation into a 19-inch
rack.
Figure 1-2 shows a 3D view of FOM-E1/T1.
Figure 1-2 FOM-E1/T1 3D View
The front panel indicates modem status. The front panel indicators and controls
are described in C
hapter 3.
The rear panel connectors and internal jumpers are described in C hapter 2 .
1.3 Functional Description
This section describes the functional circuitry of the FOM-E1/T1 fiber optic
modem. FOM-E1/T1 is used for transmission of E1 (2.048 Mbps) and T1
(1.544 Mbps) over multimode or single-mode fiber optic media. The unit is
transparent to framing and can transmit data using any framing pattern with HDB3
or B8ZS coded signals.
Figure 1-3 illustrates the FOM-E1/T1 block diagram.
DTE
Interface
Transmit Clock
Receive Clock
External Clock
CDP
Encoder/
Decoder
CDP to F/O
LED
LED
AGC, Equalizer
Clock Recovery
TD
RD
TC & RC
EXT CLK
PLL
F/O to CDP
Figure 1-3 FOM-E1/T1 Block Diagram
FOM-E1/T1 comprises the following signal processing stages:
• Signal conversion
• Data/clock recovery
• Data transfer.