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Document Number 3980-A2-GZ40-20 November 1996 Overview The Paradyne proprietary Synchronous Data Compression (SDC) feature allows an increase of throughput in data transmission, and has an error correcting procedure so that transmitted data is less sensitive to channel disturbances. The ITU-T recommendations V.42bis and V.42 have data compression and error correcting (EC) procedures for DCEs connected to asynchronous DTEs.
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9. Scroll through the installed options. SDC is listed among them. DATA ERROR COMPRESSION CORRECTION FUNCTION FUNCTION CONTROL FUNCTION key until SDC appears. keys to move the cursor to each digit position. November 1996 SIGNAL CONVERTER LINE 495-14785 key until Status appears. Press F1. 3980-A2-GZ40-20...
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When extended result codes are set to contain the data compression protocol, and SDC is active, connect messages include the characters V42t. For example, when a modem with SDC active connects to a dial line at 33,600 bps, the result code CONNECT 33600/V42t/RX=33600/TX=33600 is sent to the DTE. 3980-A2-GZ40-20 November 1996...
SDC Idle Fill SDC Bit Encoding Sync DTE CRC SDC Delay Min Sync Flow Control TX Buff Disc Delay RX Buff Disc Delay Max Frame Size Cellular Enhance DTE Interface (see Table 2) Sync DTE Rate Tx Clock Source November 1996 3980-A2-GZ40-20...
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NRZ – Causes the modem to use the standard Non Return to Zero bit encoding scheme. NRZI – Causes the modem to use the Non Return to Zero Inverted bit encoding scheme. The AT command for SDC Bit Encoding is S31= n . See Table 4, page 11. November 1996 3980-A2-GZ40-20...
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CTS_SyncDTE – CTS signal circuit (106) is set to OFF when the modem is unable to accept supplementary data from the DTE. The AT command for Sync Flow Cntrl is #Q n . See Table 3, page 9. November 1996 3980-A2-GZ40-20...
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Cellular Enhancement. When enabled, the modem uses non-standard techniques to enhance V.42 operation for cellular applications. It is still compatible, however, with modems which do not have the cellular enhancement implemented or enabled. The AT command for CellularEnhance is S91= n . November 1996 3980-A2-GZ40-20...
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Pin 15 (TXC) of the EIA-232-D interface. NOTE: RXC_Loop does not appear if SDC is enabled. NOTE: TMp tributaries are forced to RXC_Loop. The AT command for Tx Clock Source is &X n . Table 2 November 1996 3980-A2-GZ40-20...
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Sync Comp Mode. Synchronous Compression Mode. Enables and disables synchronous data compression. #SC0 Disable Synchronous Data Compression mode. #SC1 Enable Synchronous Data Compression mode. The factory setting is Disable. 3980-A2-GZ40-20 Table 3 AT Commands for SDC Description November 1996 DCP LCD Command...
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15 = 4800 bps 16 = 2400 bps 17 = 1200 bps The factory setting is 128,000 bps. Table 4 (1 of 2) S-Registers for SDC Description November 1996 DCP LCD Command Sequence Configure\Edit\ V42/MNP/Buffer Configure\Edit\ V42/MNP/Buffer Configure\Edit\ DTE Interface 3980-A2-GZ40-20...
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Determines whether the CRC of the DTE frame is transmitted from modem to modem. Register has the following values: 0 = Ignore 1 = CRC16 The factory setting is Ignore. 3980-A2-GZ40-20 Table 4 (2 of 2) S-Registers for SDC Description November 1996...
LAPM frame (DCE frame) is identical to the HDLC frame. The data from the DTE is compressed into the information field of the DCE frame. After compression, one DTE frame is segmented into one or several DCE frames. CONTROL INFORMATION Figure 3. Synchronous Data Format November 1996 FLAG 495-14783 3980-A2-GZ40-20...
Tx Clock Source configuration option setting to External (provided the DTE can support the required transmit clock signal) or change the length of the DTE cable. Figure 4. Clocks at the DTE–DCE Interface 3980-A2-GZ40-20 NOTE XTCLK (113) TXC (114)
The SDC Negotiation configuration option determines how two modems connect when one or both modems have SDC enabled. Two settings are available in the SDC Negotiation configuration option: LAPM_Buffer and LAPM_Discon. Table 5 shows the six possible SDC Negotiation configuration scenarios. November 1996 3980-A2-GZ40-20...
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If SDC is enabled, six performance measurements related to SDC can be displayed on the DCP. These measurements are available in the SDC submenu of the Status branch and are divided into two groups: TX (transmit) measurements and RX (receive) measurements. Call_Setup 3980-A2-GZ40-20 Table 5 Answering Modem SDC enabled.
The calculation does not include the DCE interframe time fill. The ratio between the number of bits per second received from the line, and the line rate. The calculation does not include the DCE interframe time fill. 3980-A2-GZ40-20...
The Software is copyrighted and/or contains proprietary information protected by law. All Software, and all copies thereof, are and will remain the sole property of Paradyne or its suppliers. Paradyne hereby grants you a personal, non-transferable and non-exclusive right to use the Software on a single modem.
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This license is effective until terminated. You may terminate it at any time by destroying the documentation and requesting that Paradyne disable or delete the Software on your modem. It will also terminate automatically if you fail to comply with any of the terms and conditions of this Agreement.