Patton electronic 2073 Switches S1-5 and S1-6 Transmit Clock Source, V.54 Prep Phase Reception

Switches S1-5 and S1-6: Transmit Clock Source

Use Switches S1-5 and S1-6 to configure the 2073 transmit clock source. In campus applications, in which two Model 2073s operate as short range modems, set one unit for internal or external clock, and the other unit for Network (Campus) Clock. When the Model 2073 termi- nates a 64kbps G.703 line and provides a serial interface to customer premises equipment, set the unit for Network (Normal) Clock.

Transmit Clock Source	S1-5	S1-6
Internal	Off	Off
External	Off	On
Network (Normal)	On	Off
Network (Campus)	On	On

NOTE: Switches S1-5 and S1-6 determine the source of clocking across the G.703 connection. Therefore, this option must be defined in both Asynchronous and Synchronous DTE applications. External transmit clock source is not a valid setting for asynchronous applications.

Switch S1-8: Local V.54 Preparatory Phase Reception Enable/Disable

Use switch S1-8 to control the reception of the V.54 remote digital loopback preparatory phase bit pattern by the local Model 2073. When this switch is “On”, the local 2073 will respond to any V.54 loopback requests that are received from the G.703 network. This is the normal setting. This setting will allow the local Model 2073 to enter V.54 loop- back when a valid V.54 preparatory phase bit pattern is received from the G.703 network.

V.54 Prep Phase Reception	S1-8
Disabled	Off
Enabled	On

When S1-8 is “Off”, the local Model 2073 will ignore any V.54 loop- back requests that are received from the G.703 network. This mode can be used to prevent the local Model 2073 from entering V.54 loop- back mode indadvertently, due to bit streams that resemble the V.54 preparatory phase pattern. Even if S1-8 is “Off”, the local Model 2073 may still initiate a V.54 loopback request.

3.1.2 Configuration DIP Switch Set “S2”

S2 Summary Table

Position	Function		Factory Default
S2-1	Timing Mode	Off	Clear Channel
S2-2	BPV Transmit Control	Off	BPV not inserted
S2-3	Front Panel Switch	On	Enabled
S2-4	DTE Test Mode	On	Acknowledged
S2-5	Reserved	Off
S2-6	Reserved	Off
S2-7	Reserved	Off
S2-8	Reserved	Off

Switch S2-1: Clear Channel or Octet Timing Mode

Use Switch S2-1 to control the G.703 timing mode. When S2-1 is set to the “Off” position, a clear channel mode of operation is select- ed. In this mode, only user data is transmitted to and from the DTE interface at any one of the data rates mentioned in section 3.1.1.

When S2-1 is set to the “On” position, 128K octet timing mode is

Clear Channel or Octet Timing Mode	S2-1
Clear Channel Mode	Off
Octet Timing Mode	On

selected. In this mode 64 kbps octet timing information is embedded within the 64 kbps user data, thus creating a 128 kbps synchronous data stream to and from the DTE.

NOTE: Octet timing mode requires synchronous, 128 kbps DTE operation. When octet timing mode is selected (S2-1=”On”), all data rate selection switch- es are ignored.

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