1. Reference Document1 How to tune Telephone Modem Kaihatsu Techno Centre Pvt. Ltd. 2002 Visit us on: http://www.ktcpl.comhttp://www.ktcpl.com This presentation is a property of Kaihatsu Techno Centre Pvt. Ltd. This is intended for the restricted use for the customers and prospective clients of Kaihatsu Techno Centre. This is a reference document only. The information given in this presentation is correct up-to the knowledge of the company. However this information is only for reference and can not be used by any one against Kaihatsu Techno Centre for any legal matters. The use of this document is only for general guidelines about selecting the best possible network link for his/her application. This presentation can not be considered for any loss of data or any other loss. This presentation must be utilised in full with total 13 pages. This presentation or the writer or Kaihatsu Techno Centre can be held responsible for any loss what so ever. The pricing given in this document may vary depending on the market situation. The pricing is given for comparison only and it should not be treated as an offer from Kaihatsu Techno Centre Pvt. Ltd. This presentation has 13 pages including this one. The figures, symbols and names used in this presentation is a trade mark property of respective individual or company.

2. Reference Document2 Introduction Although with lot of plug & play hype, it is not very easy to tune the telephone modem for best, uninterrupted data transfer. The tuning of telephone modem does need a good expert. This is true specially in India where there are various types of exchanges, long wires, unprofessional last mile wiring.

3. Reference Document3 Problems in India There are two main issues while tuning modems in India. Impedance and wiring. Every telephone exchange has a different impedance in India. They can range from 75 Ohms to 1,606 Ohms. This is because these exchanges are imported from various countries having own standards. The same is applied for intercoms as they also has various impedances. In many cases, the wiring is done in a non professional way. Too many T and Y joints, parallel connections, telephone wires running in conjunctions with power lines. Inconsistent signal voltage levels.

4. Reference Document4 Results of these problems Frequent Disconnection. Long Time for getting connected. Too much noise. Slow data transfer rate.

5. Reference Document5 How to Solve the problems? First inspect the physical wiring. Separate the telephone wires from the power lines. Avoid T & Y junctions. Use proper telephone wire. Single stand, two pair twisted wire. Avoid bundling of excess wires. Use proper telephone sockets (RJ11) If you are using intercom having impedance adjustment facility, then adjust the impedance of exchange same to that of modem and the wire.

6. Reference Document6 Tuning the Modems Modems can be tuned using AT command set. Open HyperTerminal program on PC on which modem is connected. [Start -> Program -> Accessories -> Communication] Select the Modem port Press Connect button Type ATZ and press enter. You should see a response OK If you get this response, it means modem is properly connected. Now next slides gives various command options. Please type the same way. After you have tuned all the commands, keep the final command in advance settings. [Start -> Control Panel -> Phones & Modems -> Properties -> Advance -> Connect String]

7. Reference Document7 Tuning Type CommandWhat it actually does AT Q0 V1 (OK)Display the full result code, Good for diagnostics AT S07 = 200 S10 = 200 (OK)Set connection time and disconnect time to 20Sec. Good for India. Hence even if the carrier is lost for 20 sec, modem will not disconnect. AT &K0 or K3 or K4 (OK)This is a flow control bit. 0 means no flow control 3 means software and 4 means hardware. This must be the same as PC port setting where modem is connected. AT –V90=n (OK)Automatic baud rate adjusted in V.90 protocol. When n is 1 then it is automatic. When n = 2 it is minimum 28kbps and when n = 21 it is maximum 56 kbps AT %C0 or C1 (OK)Data Compression is set ON/OFF. This is dependent on type of exchange. Try and set for best possible way. AT S6 to ATS15 (OK)This adjust the signal gain. If the wires are long then one needs to increase the gain. This is dependent on type of location. Try and set for best possible way. AT %T19,0,1E (OK)1E is a code for India. This will set the dial tone detection for India. AT %E0 or E1 or E2 (OK)E2 makes the modem to automatically drop the performance based on line quanlity AT S30 = 10 (OK)Modem will not disconnect even if the data is not sent or received till 10 min. AT &C0 or C1 (OK)Data Carrier Detect should be made On / Off

8. Reference Document8 Tone Detection in India Type CommandWhat it actually does AT %T19,0,1E (OK)1E is a code for India. l AT %T21,13,3 (OK) AT %T21,21,0(OK) AT %T21,11,110 (OK) AT %T21,12,200 (OK) AT %T21,14,110 (OK) AT %T21,15,110 (OK) AT %T21,24,0 (OK) AT %T21,29,15 (OK) AT %T21,2A,25 (OK) AT %T21,2D,100 (OK) AT %T21,2E,200 (OK) Ringing & Busy tone needs to be detected so that the software can dial again till the line is free. This auto redialing facility as well as auto connect facility of the software needs to detect the ringing & busy tone. The Indian tones are somewhat different than other countries. Here is the code to detect the same

9. Reference Document9 Intercom Originating Mode Type CommandWhat it actually does AT C1 (OK)Keep Carrier ON AT N1 (OK)Do the handshaking with remote modem AT X4 (OK)Show the result code during connection In the Intercom mode, the originating PC modem needs to be configured with following commands. These are the additional commands than the previously stated commands.

10. Reference Document10 Intercom Receiving Mode Type CommandWhat it actually does AT S0=2 (OK)Modem will automatically answer a call after 2 rings. Minimum can be 1 ring. O means it will never answer a call. In the Intercom mode, the receiving PC modem needs to be configured with following commands. These are the additional commands than the previously stated commands.

11. Reference Document11 Diagnostic Commands Type CommandWhat it actually does AT In (OK)Value of n can be from 0 to 9. Typing this command will give various information about modem. E.g. manufacturer, model name, firmware version, memory etc. AT S? (OK)Will give the detail listing of all settings of S register AT V? (OK)Will give information about all modem settings Following commands can be used for diagnostic purpose.

12. Reference Document12 Windows Xp Setup Receiving Side: Start -> Connect to -> Show all connection -> Create a new connection -> Setup an advance connection -> Accept incoming connection -> Select the modem -> select the rights -> Apply. Transmitting Side: Start -> Connect to -> Show all connection -> Create a new connection -> Connect to Network at my place -> Dial up Connection - > Select the modem -> select the rights -> Apply. Remote Windows: Windows can take a control of remote PC on modem. Note that this feature is available only on Windows Xp professional. Home edition of Xp does not support remote window monitoring. Although home edition Xp can be monitored by professional edition but not vise versa. Start -> All programs -> Accessories -> Remote Desktop -> Select modem -> Apply

13. Reference Document13 Thank you. Property of Kaihatsu Techno Centre Pvt. Ltd. This presentation is a property of Kaihatsu Techno Centre Pvt. Ltd. This is intended for the restricted use for the customers and prospective clients of Kaihatsu Techno Centre. This is a reference document only. The information given in this presentation is correct up-to the knowledge of the company. However this information is only for reference and can not be used by any one against Kaihatsu Techno Centre for any legal matters. The use of this document is only for general guidelines about selecting the best possible network link for his/her application. This presentation can not be considered for any loss of data or any other loss. This presentation must be utilised in full with total 13 pages. This presentation or the writer or Kaihatsu Techno Centre can be held responsible for any loss what so ever. The pricing given in this document may vary depending on the market situation. The pricing is given for comparison only and it should not be treated as an offer from Kaihatsu Techno Centre Pvt. Ltd. This presentation has 13 pages including this one. The figures, symbols and names used in this presentation is a trade mark property of respective individual or company. Quit Show