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Introduction

Thank you for purchasing the Tahoe 671 modem.   We did our best 

to ensure highest reliability and performance of our products. Devoting 
many years of research and development we are proud to provide a 
superior quality device unfolding new possibilities for the use of the 
copper lines.

®

Tahoe  

671

 is a G.shdsl+ modems allowing data transmission 

with speeds up to 2048 kbps over a 2-wire line. Thanks to powerful 
TCPAM-32 modulation throughputs and ranges are much higher than 
using HDSL technique. TCPAM-16 modulation is also available to provide 
compatibility with other manufacturers’ products.

The modem is equipped with a G.703 interface that may work in 

both framed or unframed mode. In the first case only selected timeslots 
may be transmitted over long lines where the throughput of 2048 kbps 
cannot be achieved.

The modem may be managed using a built-in LCD and keyboard, 

using a serial console or remotely through the DSL line.

The system firmware is stored in the Flash memory - it is possible 

to update it through the serial console. The configuration is stored in the 
EEPROM memory.

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Tahoe  671 (G.shdsl+ / G.703 modem)

User Manual

http://www.tahoe-group.com/

Firmware version 1.2.6

®

©2004 Tahoe . All rights reserved.

Other trademarks of other companies are used only for explanation and to 

the owner's benefit, without intent to infringe. 

®

Tahoe  assumes no responsibility for any errors or omissions that may appear in 

®

this document. Tahoe  makes no commitment to update the information 

contained here, and may make changes at any time without notice.

Summary of Contents for 671

Page 1: ...FREEDOM OF COMMUNICATION USER MANUAL G shdsl modem with G 703 interface TAHOE 671 ...

Page 2: ......

Page 3: ...i TABLE OF CONTENTS 1 Introduction 1 2 Interfaces 2 3 Modem configuration using built in keyboard and LCD 4 4 Configuration using serial console 10 5 Technical data 12 6 Declaration of Conformity 13 ...

Page 4: ...ther trademarks of other companies are used only for explanation and to the owner s benefit without intent to infringe Tahoe assumes no responsibility for any errors or omissions that may appear in this document Tahoe makes no commitment to update the information contained here and may make changes at any time without notice ...

Page 5: ...oughputs and ranges are much higher than using HDSL technique TCPAM 16 modulation is also available to provide compatibility with other manufacturers products The modem is equipped with a G 703 interface that may work in both framed or unframed mode In the first case only selected timeslots may be transmitted over long lines where the throughput of 2048 kbps cannot be achieved The modem may be man...

Page 6: ...lines written in bold are necessary for transmission Terminal settings are 9600 bps 8 data bits 1 stop bit no parity no handshaking Pin Name 1 DCD 2 3 4 5 6 RXD TXD DTR GND DSR Description carrier detect transmission readiness signaling data received from the PC data sent by the modem to the PC active when the PC is switched on signal ground active when the modem is switched on 7 RTS used by the P...

Page 7: ...n the industry thus in most cases a regular straight patch cord may be used to connect the card to the external device Anyway the pinout should be carefully checked before connecting the DCE device The RX pin of the card should be connected to the TX pin of the other device the RX pin to the TX pin TX to RX and TX to RX 2 3 Pin Signal 1 Tx 2 3 4 5 6 Tx Rx Rx 7 8 ...

Page 8: ...eans that the carrier signal was detected In the case of unframed mode letters SC may appear there Letter S means that the modem is synchronized to the E1 stream Letter C again signals that the carrier was detected If only C is displayed then the G 703 signal is present but the converter is unable to synchronize to it Perhaps the signal detected is an unframed signal On the right of the display th...

Page 9: ...t is set to 2048 kbps 1984 and up button is pressed the letters unfr will appear in the brackets It means that the unframed mode is enabled and whole 2048 kbps are used for data transmission In the framed mode the selection of G 703 timeslots used for data transmission is done automatically depending on the throughput set Timeslots 0 synchronization and 16 signaling are selected first then the sub...

Page 10: ...h gives better immunity for signal attenuation and higher reach The second part PAM or TCPAM means either the Pulse Amplitude Modulation or Trellis Coded Pulse Amplitude Modulation The latter is more efficient It is recommended to use the 32 TCPAM modulation which provides the best results The remaining line codings are available to provide compatibility with others manufacturers equipment The 32 ...

Page 11: ...r 43 dB 2000m 3 7 Test loopbacks The test loopback are useful to diagnose the network problems Two kinds of loopback are available towards DSL packets received from the G shdsl line are sent back to it towards PCM packets received from the G 703 port are sent back to it 3 8 Console throughput Different console port throughputs may be chosen 9600 19200 or 38400 bps Be sure to set the same throughpu...

Page 12: ... shdsl link will be disconnected and negotiated again 3 12 Modem reset After pressing Enter the whole modem is rebooted If some settings were not saved to the EEPROM they will be lost 3 13 Line parameters The Esc button returns to the main screen with modem type throughput and link state While having this screen displayed you may press Enter to display line attenuation in dB proper value appears o...

Page 13: ...the synchronization When the NMR is less than 0 dB modems will be unable to bring the link up It is the best practice to keep the NMR equal to or higher than 7 8 dB so the error rate will be unnoticeable Otherwise the packets will be lost due to bit errors and the retransmission would be necessary thus decreasing the overall effective throughput Pressing Enter again will return to the main screen ...

Page 14: ...t arrow should be pressed to select an option To confirm a changed parameter press Enter To cancel a parameter change press left arrow All options are identical to the LCD options described in point 3 However two options were added Manage remote modem and Refresh screen 4 firmware version and compilation date time elapsed since power on or reboot log containing most important information about mod...

Page 15: ...king message will appear on the top of the screen informing that the connection was made Now all the options on the screen concern the remote modem They may be changed and stored to the EEPROM The Manage remote modem option will change to Return to local modem Selecting it will cease the remote management 4 2 Refresh screen When a working converter is connected to the PC s serial port the screen c...

Page 16: ... G 704 or unframed balanced 120W RJ 45 connector throughput 64 1984 kbps or 2048 kbps line coding AMI HDB3 signaling FAS CCS CRC4 receiver sensitivity 12 dB 43 dB range 50m 2000 m serial console RS 232 DB9 M connector dimensions 200 mm width x 45 mm height x 130 mm length power supply 15 V 230 mA 3 5W external power supply included environmental conditions storage temperature 20 C to 65 C humidity...

Page 17: ...mmunication terminal equipment requirements The compliance of Tahoe 671 with the requirements of the above mentioned directives is ensured by complete application of the following harmonized European Standards EN 60950 2000 EN 55022 1998 EN 61000 6 1 2002 EN 61000 6 3 2002 Signed Piotr Kaczmarzyk Position Director Signature Date 2 Feb 2004 Place Wroclaw Poland TAHOE Piotr Kaczmarzyk ul Uniwersytec...

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Page 20: ... TAHOE Uniwersytecka 1 50951 Wroc aw Poland phone 48 50 100 7362 fax 48 71 344 2642 http www tahoe group com ...

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