3.0CONFIGURATION
The Model 1186 is equipped with eight DIP switches, which allow configuration of the unit for a wide variety of applications. This section describes the switch location and explains all possible configurations.
3.1 CONFIGURE THE HARDWARE DIP SWITCHES
The 8 external dip switches are accessible from the underside of the Model 1186 (See Figure 2, below).
Rear | Front |
On
S1
Off
Figure 2. Underside of Model 1186, showing location of the DIP Switches
Figure 3 shows the orientation of the DIP switches in the ÒONÓ and ÒOFFÓ positions.
ON
OFF
Figure 3.
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3.1.1 Configuration of Model 1186
Switches S1 through S8 may be used to configure clocking modes and line coding. Default settings of the switches are shown in the table below. A description of the switch options follows the table.
Position | Function | Default Setting | |||||
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S1 | Clock Source | ON |
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S2 | Clock Source | ON |
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S3 | Line | OFF |
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S4 | Coding | OFF |
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S5 |
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S6 | Reserved for Future Applications | OFF |
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S7 |
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S8 |
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Switches S1 and S2: Clock Mode
Use Switches S1 and S2 to determine clock mode of the 1186.
S1 | S2 | Setting | Description |
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On | On | Internal | Transmit clock generated internally | |
On | Off | Receive Recover | Transmit clock derived from the line | |
Off | On | Network | Transmit clock derived from G.703/G.704 | |
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| equipment interface | |
Off | Off | Not Used | Internal use only |
Note: The Model 1186 units are intended to work in pairs. When setting the clock modes for the Model 1186 units, one end of the link must be set for Receive Recover and the other end must be set for either Internal or Network.
Switch S3 and S4: Line Coding Options
Use Switches S3 and S4 to determine whether the G.703/G.704 line coding is HDB3 or AMI (for older telecommunications equipment). The line coding must be the same line coding prescribed by the NAP (Network Access Provider). Most applications will use HDB3.
High Density Bipolar 3 (HDB3): In HDB3 coding, the transmitter deliberately inserts a bipolar violation when excessive zeros in the data stream are detected. The receiver recognizes these special vio-
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