| Eugene Yong 03/07/07 15:31 Modified: 03/07/07 15:46 Read: 1383 times Malacca Malaysia |
#134551 - TxD pin to TxD pin? Responding to: Eugene Yong's previous message |
1. When i was reading a website regarding serial communication and its related signal pins, i came across this quote saying that the TxD pin of the DTE (in this case 8051) is supposed to be connected to TxD pin of the DCE (modem). This is also called as straight through cable. The question here, is why? I thought the TxD of DTE is supposed to be connected to RxD of DCE since the DCE is supposed to accept command from the DTE.
The transmit pin from the PC transmits to the "transmit" pin of the modem (but actually the modem is receiving the data from this pin so from the point of view of the modem it would be a receive pin). This is the link to the site : http://tldp.org/HOWTO/Serial-HOWTO-20.html 2. Also, how am i supposed to know whether the modem has successfully execute each AT Command i fed into it (before i send additional AT Command)? Is this sufficient just by looking at the TI flag everytime i send out a the last character of a command (Meaning, i am allowed to send new command once the TI flag is asserted)? Or must i wait for a status signal via CTS from the modem? |
| Topic | Author | Date |
Serial Communication Related Problem  | Eugene Yong | 03/06/07 10:49 |
| partial answers | Patrick De Groote | 03/06/07 11:07 |
| Oh yeah, i forgot about that | Eugene Yong | 03/06/07 12:09 |
| FIRST, THEN, THEN, THEN | Erik Malund | 03/06/07 11:10 |
| A little bit of sarcasm as usual but often helpful | Eugene Yong | 03/06/07 12:25 |
| Proper baud rate... | Dave Brooks | 03/06/07 12:52 |
| baud rate | Erik Malund | 03/06/07 13:01 |
| calculator | Dave Brooks | 03/06/07 13:11 |
| modem is autobauding | Jan Waclawek | 03/06/07 16:04 |
| Noted | Eugene Yong | 03/06/07 21:00 |
| Some answers | Lynn Reed | 03/06/07 11:14 |
| Thanks for a patience reply | Eugene Yong | 03/06/07 12:33 |
| Nothing to add, but ... | Joseph Hebert | 03/06/07 11:29 |
| i second(ed) that motion | Erik Malund | 03/06/07 11:44 |
| My location profile? | Eugene Yong | 03/06/07 12:38 |
| with this known, it would do no good ... | Erik Malund | 03/06/07 12:40 |
| Radio Shack | Lynn Reed | 03/06/07 12:45 |
| Even so | Neil Kurzman | 03/06/07 20:44 |
| I can buy it from the local electronic shop | Eugene Yong | 03/06/07 20:52 |
| Sarcasm | Neil Kurzman | 03/06/07 20:52 |
| I agree | Eugene Yong | 03/06/07 20:57 |
| Thanks for understanding and recommendation! - NT | Eugene Yong | 03/06/07 12:35 |
| More info | Russell Bull | 03/06/07 22:28 |
| you need to understand the parameters. | Mike Stegmaier | 03/07/07 06:28 |
| "more valid" evidently means invalid | Erik Malund | 03/07/07 07:04 |
| not quite | Patrick De Groote | 03/07/07 07:29 |
| What a wonderful example that when total crap is s | Erik Malund | 03/07/07 07:44 |
| lesson | Patrick De Groote | 03/07/07 11:43 |
| No, it doesn't | Andy Neil | 04/03/07 00:37 |
| TxD pin to TxD pin? | Eugene Yong | 03/07/07 15:31 |
| dte-dce-dce-dte | Patrick De Groote | 03/07/07 16:00 |
| Noted! Thanks! | Eugene Yong | 03/07/07 16:20 |
| same request question | Jecksons Ben | 03/07/07 21:38 |
| Meaning of "Transmit" | Andy Neil | 04/03/07 04:37 |
| same request question 2 | Jecksons Ben | 03/07/07 21:54 |
| Initial command sending code; help me take a look! | Eugene Yong | 03/09/07 01:50 |
| Make it simple for yourself | Russell Bull | 03/09/07 02:50 |
| Why the need of circular buffer? Receiving? | Eugene Yong | 03/09/07 04:05 |
| polling versus interrupt | Patrick De Groote | 03/09/07 05:17 |
| Check OK string at RXD or DCD at interupt? | Jecksons Ben | 03/09/07 21:27 |
| no good | Patrick De Groote | 03/10/07 02:14 |
| Voice mode only! No data communication. | Eugene Yong | 03/10/07 04:09 |
| you are missing the basics | Patrick De Groote | 03/10/07 04:26 |
| NO carrier sent after DCD didn't found | Jecksons Ben | 03/11/07 19:54 |
| I do not agree | Patrick De Groote | 03/12/07 00:37 |
| Interupt DCD signal for clear transmission | Jecksons Ben | 03/15/07 01:15 |
| For Voice Dialling | Muhammad Fauzan | 03/19/07 12:33 |
| and by the way | Muhammad Fauzan | 03/19/07 12:36 |
| Sorry for multiposting | Muhammad Fauzan | 03/19/07 12:58 |
| The ";" works but... | Eugene Yong | 03/22/07 19:46 |
| ";" to return to idle state | Muhammad Fauzan | 03/24/07 16:48 |
| +++ with 3 seconds no modem activity | Charles Bannister | 03/25/07 03:41 |
| +++ escape sequence | Andy Neil | 03/25/07 07:07 |
| Monkey See. Monkey Do. | Charles Bannister | 03/25/07 08:14 |
| Now monkey also understand? | Andy Neil | 03/26/07 00:26 |
| Are you mistaken? | Eugene Yong | 03/25/07 23:36 |
| I think so | Andy Neil | 03/26/07 00:24 |
| Circular buffers | Russell Bull | 03/23/07 00:42 |
| Initial code for receiving modem response | Eugene Yong | 03/26/07 10:38 |
| don't fiddle with the timer, let it run | Erik Malund | 03/26/07 10:43 |
| Understood, will run TR1 in global init, thx! - NT | Eugene Yong | 03/26/07 10:48 |
| check this out, Eugene... | Dave Brooks | 03/26/07 10:52 |
| Ah! Didn't know that! Thanks! -NT | Eugene Yong | 03/26/07 11:09 |
| Code; modem commands & responses | Andy Neil | 03/26/07 11:23 |
| V.250 (formerly V.25-ter) - get it free! | Andy Neil | 03/26/07 14:28 |
| code,modem command and response | Jecksons Ben | 04/01/07 20:20 |
| system froze when connected to hyperterminal | Eugene Yong | 04/02/07 13:39 |
| Your code... | Russell Bull | 04/02/07 23:48 |
| It should not be a hardware problem since.. | Eugene Yong | 04/03/07 01:43 |
| Not necessarily | Andy Neil | 04/03/07 02:42 |
| Just taking a stab at it... | Chris Singer | 04/03/07 10:22 |
two 'ugly' guesses | Erik Malund | 04/03/07 10:44 |