User manual EPSON ESC-VP21

[. . . ] FAX/DATA MODEM USER'S MANUAL Notice: Hayes is a trademark of Microcomputer Products Inc. Publication Number : ASK9406 Table of Contents FCC/DOC REQUIREMENTS . 26 Time Independent Escape Sequence (TIES) . 53 Local Analog Loopback with Self-Test . 57 Remote Digital Loopback with Self-Test . [. . . ] The default value of 16 optimizes throughput for most file types. n=6-250=Number of characters 2. 3 Dial Modifers This section describes all of the dial modifiers which are used in dial strings. Wait for Quiet Answer Cause the modem to wait for specified amount of time (S-register S7) followed by 5 seconds of silence before processing the next dial modifier. @ 26 COMMAND REFERENCE - 2 , Pause ", ", placed anywhere in the dial string, tells the modem to pause for the number of seconds specified by S-register S8 before processing the rest of the dial string. ! Initiate a Hookflash "!", placed anywhere in the dial string, tells the modem to initiate a hookflash, which means to hang up for 0. 75 seconds and then go off-hook again before processing the rest of the dial string. This modifier allows access to PBX features like call transferring. -( ) Ignored by Modem These four characters are ignored by the modem, but space may be included in the dial string for separating area codes and numbers. Return to Idle State Causes the modem to enter on-line command mode without initiating a data modem handshake (used for phone directory auto-dialers). 2 - COMMAND REFERENCE 27 P Pulse Dialing P, placed ahead of a number, tells the modem to dial a number using pulse dialing. R Reverse Originate Mode to Answer Mode R, which can only be placed at the end of the dial string, tells the modem to change from the originating mode to the answer mode once it dials all the digits before the R. This modifier is used to call an originate-only modem, S Dial a Stored Number S is used to dial one of four numbers stored in nonvolatile memory. For example, instead of entering a dial string, you can use this command: Command: ATDTS=1<CR> T Tone Dialing T, placed ahead of a number, tells the modem to dial a number using touchtone dialing, 28 COMMAND REFERENCE - 2 W Wait for Dialtone Causes the modem to look for dial tone for a specified amount of time. If dial tone or the amount of time specified by the S-register S6 times-out, the modem will then process the next command in the dial string. If a busy signal is detected, the modem will respond back to the DTE with a busy response code, and then go into offline command mode. 2. 4 Time Independent Escape Sequence (TIES) The Time Independent Escape Sequence (TIES) has been developed by a group of modem manufacturers as an alternative to the Hayes Escape Sequence. TIES has been designed to work with existing communication software written for the Hayes Escape Sequence. The escape sequence is sent by the host (DTE) to return the modem to command state while in the on-line data state (connected to another modem) or diagnostic mode (&Tn commands). The DTE implements the escape sequence by sending the escape character three times, followed by a valid `AT' command and the contents of S3 (typically a <CR>). Upon detecting the three consecutive escape characters, the modem changes to a TIES command mode, and starts an internal Escape Prompt Delay timer (EPD) - with the time limit as defined by S12. If the EPD timer times out, the modem sends an `OK' message to the DTE 2 - COMMAND REFERENCE 29 and then waits indefinitely for an incoming valid `AT' command string from the DTE. If the next character received by the modem is not an `A' or `a', then the modem returns to data mode and sends a `CONNECT message back to the DTE. If the modem receives an `A' or `a', the modem disables the EPD timer (if it has not time out) and sends the character to the remote modem. The modem then stores any received data from the DTE into the modem internal command buffer and sends the data to the remote modem. Upon detecting a <CR> or receiving Up to 39 data characters, the modem then determines if a valid `AT' command has been received and then processes the valid commands. If a non-'AT' command string or an invalid command string has been received then the modem will remain in data mode. If a valid `AT' command has been received, then the modem changes to command mode and sends an `OK message. After sending the `OK message, the modem will echo back any received data from the DTE while in command mode. While in TIES command mode, the modem ignores certain characters that may cause the modem to incorrectly decide that an incoming `AT' string is invalid. The ignore character are <LF>, <space>, and <CR> (<CR> is ignored only when S3 is not equal to <CR>). Not all `AT' commands are supported during TIES command mode. [. . . ] The phone line may be too noisy or the telephone cord may be poor. Also the remote modem may not recognize your modem's baud rate. Your Can't Transmit After You Have Connected to the Remote Modem In this case, check the communication parameters of the remote modem, then configure your software to the same number of data bits, stop bit, and parity. 64 TROUBLESHOOTING GUIDE - 5 Fig. 5-1 Troubleshooting Flowchart 5- TROUBLESHOOTING GUIDE 65 Finding the Source of Transmission Errors A failure in modem communication is usually characterized by unacceptably high error rates or a total inability to communicate; it may be the fault of the local computer or terminal, the local modem, the telephone line, the remote modem or terminal. Figure 5-1 gives an algorithm for finding the source of errors. If you have any further questions or problems, please contact your dealer. 66 TROUBLESHOOTING GUIDE - 5 6- APPLICATION EXAMPLES 6. 1 Dialing a Remote Modem Command line: ATDP9WT002, (886)-7128423<CR> This command line instruct the modem to dial a remote modem through a PBX. [. . . ]