The document discusses digital data transmission and interfaces. It describes different transmission methods like parallel and serial transmission and synchronous and asynchronous transmission. It also discusses Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) interfaces, and interface standards like EIA-232. Modems are discussed as devices that convert digital signals from DTEs to analog signals for transmission and vice versa. Various figures illustrate these concepts.

1. Chapter 6
Transmission of
Digital Data
Interfaces and Modems
• Digital Data Transmission
• DTE-DCE Interface
• Other Interface Standards
• Modems
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2. Figure 6-1
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3. Parallel Transmission
Figure 6-2
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4. Serial Transmission
Figure 6-3
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5. Asynchronous Transmission
Figure 6-4
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6. Synchronous Transmission
Figure 6-5
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7. DTEs and DCEs
Figure 6-6
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8. DTE-DCE interface
Figure 6-7
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9. Sending Data
Figure 6-8
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10. Control
Figure 6-9
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11. EIA-232
Figure 6-10
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12. Data Pins
Figure 6-10-continued
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13. Control PinsFigure 6-10-continued
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14. Timing Pins
Figure 6-10-continued
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15. Other Pins
Figure 6-10-continued
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16. Figure 6-11
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Synchronous Full-Duplex Transmission

17. Figure 6-11-continued
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Synchronous Full-Duplex Transmission

18. Figure 6-12
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Pin Connection With and Without DCEs

19. Figure 6-12-continued
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Pin Connection With and Without DCEs

20. Figure 6-13
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Null Modem