Paradyne COMSPHERE 3810, COMSPHERE 3820, COMSPHERE 3811, COMSPHERE 3800 Information Sheet

TM

COMSPHERE 3800 Series Modems
V.29 and V.33 Leased Line Options
Information Sheet

Document No. 3800-A2-GB61-10

November 1996

V.29 and V.33 Options

Customers who select the V.29 or V.33 Leased Line Options receive firmware Release 4.32.50. This release
differs from the firmware release described in the COMSPHERE 3800 Series Modems, Models 3810, 3811, and

3820 User’s Guide (3810-A2-GB91) in several respects. There is no fax capability in Release 4.32.50, and
references to it in the User’s Guide should be ignored. Other differences are in options available through the

Diagnostic Control Panel or the AT command set. The following tables show these differences, and should be
used in lieu of the respective sections of the User’s Guide. The page numbers shown refer to those sections.

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Table 1 shows the changes to the User’s Guide for DTE Interface Configuration Options when the V.29 or V.33
Option is installed.

Table 1

DTE Interface Configuration Options

RTS Action: Ignore
Nxt Ignore Stndrd_RS232 Sim_Cntl_Car Cntl_Car

User’s Guide, p. 8-18.
Request-to-Send Action. RTS is a signal from the DTE to the modem indicating the DTE has data to send to the modem.

Ignore – Modem assumes RTS is always ON. Use this selection when the DTE does not provide RTS to the modem.
Standard RS232 – Allows the DTE to control RTS to the modem in normal EIA-232-D operation. RTS must be ON for

the DTE to transmit to the modem.
Simulated Control Carrier – RTS input controls the remote modem’s LSD signal. This is used for DTEs that require

Line Signal Detect (LSD) to toggle ON and Off to simulate half-duplex operation.
NOTE: If RTS Action is set for simulated control carrier, then the remote modem’s LSD Control configuration

option must be set for Simulated Control Carrier. Simulated Control Carrier conforms to V.13
specifications. This setting is ignored when the modem is configured for Asynchronous mode and
RTS/CTS flow control is selected.

Control Carrier – Allows the DTE’s RTS signal to control the modem’s carrier signal. When RTS is ON, carrier is
present on the VF line. When RTS turns Off, carrier is no longer present. This is only valid for V.29 leased-line
modulation.

For Async Dial and UNIX Dial, Ignore is the factory default.
For Sync Dial and Sync Leased, Stndrd_RS232 is the factory default.

AT command for Standard RS232 is &R0.
AT command for Ignore is &R1.
AT command for Simulated Control Carrier is &R2.
AT command for Control Carrier is &R3.

CT111_Rate Cntl: Disable
Nxt Disable Fallback1 Fallback2

User’s Guide, p. 8-22.
CT111 Rate Control. Allows the DTE to control modem rate via Pin 23 of the EIA-232-D interface. This configuration

option determines the effect of the DTE Rate control signal. CT111 is also known as CH on the EIA-232-D interface.

Disable – Disregards CT111 Rate Control.
Fallback1 – Forces the modem to decrease its configured data rate to the next lower data rate when CT111 is Off. Valid

only for V.32bis, V.33, and V.29 modulations. Modem will only fall back within the same modulation scheme. When
CT111 turns ON, the modem returns to its previous data rate.

Fallback2 – Forces the modem to decrease two data rates while remaining in the same modulation scheme. When
CT111 turns ON, the modem returns to its previous data rate.

NOTE: This configuration option is only valid in Async Direct mode and Synchronous mode. For proper

The factory default is Disable.
AT command is S-Register S61 =

operation, disable the V32bis Autorate and V32bis Automode configuration options.

n

, where n is 0 for Disable, 1 for Fallback1, and 2 for Fallback2.

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