COMSPHERE 392xPlus Modems
4-10 November 1996 3920-A2-GN31-30
DTE Interface — Multiport Mode l
The DTE Interface configuration options contain EIA-232-D (CCITT V
.24) and asynchronous
character format information essential for maintaining a connection and for transmitting data
between the DTEs and the modem.
Table 4-1 shows each DTE Interface configuration option as it appears on the LCD, with the Sync
Leased factory default setting (the default value if the modem is newly installed) shown following
the colon ( : ) on the first line and with all available selections listed on the second line. Following
this is a description of the configuration option. Factory default settings are listed in Appendix F.
Table 4-1
(1 of 9)
DTE Interface Configuration Options — Multiport Mode l
MUX Sub-Group
MUX Mode: TDM/MSD
Nxt TDM/MSD Disable DTE Bridge
Mux Mode. Determines the operating mode of the multiplexer (mux).
NOTE: If the MUX mode configuration option does not appear under the DTE Interface branch, refer to Table B-7 in
Appendix B,
Troubleshooting
.
TDM/MSD – Enables the modem as a time division multiplexer (TDM) and a modem sharing device (MSD). When the
Mux mode configuration option is set to TDM/MSD, and at least one port has the MSD Mode setting enabled, then the
MSD is enabled. Only the lowest numbered port in an MSD group allows strapping of the port rate, which will only be
used when V.34 or V.32 modulation is active. For example, a tributary running TMp modulation will have the port rate
equal to the line rate. The lowest numbered port on the control modem is recommended as the MSD output port.
Disable – Disables MUX Mode on the modem. Refer to the
Singleport Mode
section in this chapter for the mux disabled
configuration options.
DTE Bridge – Enables the modem as a digital bridge for dial backup of a multipoint configuration by bridging the signal
on the digital side of the Front End Processor (FEP) modems. In this configuration, only two ports can be used on the
control and backup modems (both on the FEP side). Data received on Port 1 is transmitted across the communication
link and looped back through Port 2. Data received across the communication link and on Port 2 is sent through Port 1.
NOTE: DTE Bridge mode is only available when the NetworkPosition configuration option is set to Control.
NOTE: MSD mode is only available when the NetworkPosition configuration option is set to Tributary.
Tx Clock Source: Internal
Nxt Internal RXC_Loop Port1 Port2 Port3 Port4
Transmit Clock Source. Determines the source of timing for synchronous data transmitted from the modem to the
analog channel.
NOTE: If the DTE Bridge configuration is enabled, Ports 2, 3, and 4 are not available.
Internal – The transmit data’s clock source is derived from the modem’s internal clock. This clock is available as an
output on Pin 15 (TXC) of the EIA-232-D interface.
Receive Clock Loop
– The modem’
s transmit clock is derived from its received analog signal. The derived clock is
available as an output on Pin 15 (TXC) of the EIA-232-D interface.
Port1 – The transmit data’s clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 1.
Port2 – The transmit data’s clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 2.
Port3 – The transmit data’s clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 3.
Port4 – The transmit data’s clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 4.