CANOGA PERKINS 2270 Fiber Optic Modem - Manual (Page 8)

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Canoga Perkins
Chapter 1 - General
1.1 Equipment Description
The 2270 is a high-speed modem for full-duplex operation over fiber optic cable. It operates syn-
chronously up to 20 Mbps, and asynchronously up to 5 Mbps in the sample-data mode with a 25%
jitter limit. The 2270 is available in rack-mount and standalone configurations. Both are intended to
operate with a variety of electrical interfaces (refer to Section 7.5, "2270 Fiber Optic Modem
Configurations," for a listing of the interface options for the 2270). Refer to Section 3 for detailed
descriptions of available I/O interfaces.
The 2270 has integral System Test and loopback diagnostic modes for performance monitoring.
Various 2270 configurations provide local modem controls, including those listed in Table 1-A. A
limited form of end-to-end control lead operation is also available (refer to Section 4.8).
1.2 Functions, LEDs and Switches
The 2270 standalone modems do not have an on/off switch, since they power up when plugged in.
For 2270 Rack-Mount configurations, a power supply on/off switch is located at the rear of each
power supply assembly on the 2201 Rack Chassis.
An eight-section switch bank, located on the front panel of the 2270 (see Figure 1-1), controls all
operating modes and internal clock rates.
Switch positions 1, 2 and 3 select the internal clock operating rates. Refer to Table 2-B for data
rate switch settings. The rates depend on the crystal option installed. Refer to Section 7.5 for a list
of crystal options available. The -08 crystal is installed as the factory default crystal unless an
alternate crystal is ordered.
Table 1-A. Available Modem Controls
DATA/CLOCK CONTROLS
TRANSMIT DATA REQUEST TO SEND
RECEIVE DATA CLEAR TO SEND
TRANSMIT CLOCK DATA CARRIER READY
RECEIVE CLOCK DATA SET READY