A mode switch positions 3-b locked external rates – CANOGA PERKINS 2240 Fiber Optic Modem User Manual
Page 30
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Canoga Perkins
Table 3-A.
Mode Switch
Positions
For many modes, the specific data rate must be selected. The data rate is selected
by setting four switches on the front panel (positions 1-4). Refer to Tables 3-B
and 3-C for the data rate switch settings.
Table 3-B.
Locked External
Rates
DIP Switches
(C) Closed (O) Open
Mode
5
6
7
Operating Mode
0
C
C
C
Sampled External Clock up to
1.544 Mbps *
1
O
C
C
Internal Clock Group 1 Rate
2
C
O
C
Internal Clock Group 2 Rate
3
O
O
C
Internal Clock Group 3 Rate
4
C
C
O
Internal Clock Group 4 Rate
5
O
C
O
Slave Clock
6
C
O
O
Asynchronous up to 1.500 Mbps *
7
O
O
O
External Clock with Variable Lock
Ratios (refer to Table 3-B)
* Frequency Limit assumes that user's equipment can tolerate 250 ns of pulse
distortion on the clock signal.
DIP Switches (C) Closed (O) Open
Rate Switches
Range Select
Allowable Range of External
Rate 1 2 3 4
8
Clock Frequency (Mode 7)
0
C C C C
C (Normal)
1.490 MHz to 2.060 MHz
O (Low)
1.026 MHz to 1.480 MHz
1
O C C C
C (Normal)
750 kHz to 1.025 MHz
O (Low)
513 kHz to 749 kHz
2
C O C C
C (Normal)
375 kHz to 512.5 kHz
O (Low)
256.3 kHz to 374 kHz
3
O O C C
C (Normal)
187.5 kHz to 256.2 Hz
O (Low)
128 kHz to 187 kHz