Switch SW3 and SW4: Clock Mode
SW3 is used to along with SW4 to determine the clock mode. For example the Model 2702 can be set to external clock mode by setting both SW3 and SW4 to the on position. Please refer to the Clock Mode chart below for the desired settings.
CLOCK MODE SETTINGS
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SW3 | SW4 | Clock Mode |
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Off | Off | Network (Default) |
Off | On | Internal |
On | On | External |
On | Off | Network |
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CLOCK MODES
Network Clock Transmitter timing is derived from the received line signal.
Internal Clock Transmitter clock is derived from an internal clock source
External Clock Transmitter timing is derived from the local DTE device. A 2.048 MHz timing signal must be present a at the external clock pin U and pin W on the M/34 connector.
Note: When using the 2702 as a
4.0 INSTALLATION
The Model 2702 is equipped with DTE, network, and power interfaces. This section briefly describes connection to each.
4.1 DTE INTERFACE CONNECTION
The DTE/DCE interface is a V.35 DCE presented as an M/34 male connector. This interface is designed to plug directly into a DTE inter- face (See Appendix D for V.35 interface pin assignments).
4.2 NETWORK INTERFACE CONNECTION
The Network Line Interface is an eight position keyed modular jack configured as a
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| 1 | 1 | (RX) Receive (Ring) | |
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| 2 | (RX) Receive (Tip) | ||
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| 2 | 3 | Shield | |
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| 4 | (TX) Transmit (Ring) |
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| 4 |
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| 5 | (TX) Transmit (Tip) | |
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| 6 | 6 | Shield | |
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| 7 | 7 | No connection | |
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| 8 | 8 | No connection | |
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Figure 3. Model 2702 twisted pair line interface.
NOTE: If the Model 2702 is being used for private short range modem applications, the twisted pair cable connected to its port will need to be a
SIGNAL | PIN NO. | PIN NO. | SIGNAL |
RX Data (Ring) | 1 | 4 | TX Data (Tip) |
RX Data (Tip) | 2 | 5 | TX Data (Ring) |
TX Data (Ring) | 4 | 1 | RX Data (Ring) |
TX Data (Tip) | 5 | 2 | RX Data (Tip) |
9 | 10 |