CHAPTER 5: Technical Guide

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5. Technical Guide

5.1 Control Signals

MAIN CHANNEL CONTROL SIGNALS
RTS (DCD)
• In RTS/DCD contention mode: follows RTS (DCD) of the selected sub-channels.
• In Data Contention mode: ON if one of the sub-channels RTS (DCD) is ON.
CTS On only when the CTS signals of all active sub-channels are ON. A sub-channel is active if it is
connected to a modem and the DSR signal is ON (enables connection of dialup modems to the PSD).
DSR (DTR)
ON if one of the sub-channel’s DTR (DSR) is ON.
SUB-CHANNEL CONTROL SIGNALS
RTS (DCD)
• Follows the main channel RTS (DCD) (unless the sub-channel is disabled).
CTS • In RTS contention mode: selected sub-channel follows DTS signal of main channel.
• In Data Contention mode: sub-channel receives CTS from main channel immediately after it raises
RTS (unless the sub-channel is disabled).
DSR (DTR)
Follows the main channel DSR (DTR).

5.2 Block Diagrams

Figures 6 through 9 illustrate the flow of data and control signals in the PSD, in different DTE/DCE
configurations:

Main Sub-

Figure Channel Channel

Number Configuration Configuration

6 DTE DCE
7 DTE DTE
8 DCE DCE
9 DCE DTE