1200 BPS DC-2212 Modem (260-1176) Pprogramming Faxback Doc. # 5683 A Videotex Plus communications package for TRS-80 Model II,12, and 16 microcomputers is used in the sample programming sessions following. With this package, you are able to communicate with a variety of information services and host computer systems. The examples are designed to familiar- ize you with some of the operations the modem is capable of performing. A log-on session gets you started by showing how the modem is used to log on an information service. The remaining sessions demonstrate how you can program the modem to perform operations, such as dialing your calls and answering the phone automatically. Additionally, you will learn how the advanced programming options are used to enhanced automatic operations. PROGRAMMING THE MODEM All modem functions are controlled by ASCII encoded commands that you send from your computer keyboard. A two-key code sequence called the wake-up command is used to open the modem for programming. (See WAKE UP, DC-2212! for an explanation of the importance of this command's function, page 13.) When this two-key code sequence is issued, the DC-2212 automatically adapts the speed, word length, number bits, and parity of your computer. When answering calls, the modem adapts to the speed, word length, number bits, and parity of the calling modem. 1. Check again that all peripherals are correctly connected (CONNECTING THE MODEM page 35) and receiving power. 2. Flip the power switch on the modem's front panel to the ON position. Carrier Detect (CD) indicator lights. 3. Load and run the Videotex Plus communications program as described in your user's guide. 4. At TRSDOS READY, type VIDTEX . Terminal Ready (TR) indicator lights. The screen shows: VIDTEX 01.00.00 COPYRIGHT 1983 TANDY CORP. ALL RIGHTS RESERVED 5. Set the baud rate, word size, parity, and stop bits that you want to use. 6. Open the DC-2212 modem for programming by typing the wake-up command sequence. Press <*> <.>. 7. When the * echoes on your computer screen, enter the command that tells the modem to display or list its current parameters. Press to send the LIST COMMAND. These parameters appear on the screen as: PHONE NO: 10 BITS/CHAR: Y ABORT CHAR: 14H LOSS OF CARR: Y SEND SPACE: N RECEIVE SPACE: Y ABORT ENABLE: Y HIGH SPEED: Y ANALOG LOOP: N ORIG MODE: Y MANUAL MODE: N FORCE CARDET: Y PULSE DIAL: Y SLOW DIAL: Y Since the modem is defaulted for automatic originate mode operation when cold-started, the list should show: ORIG: Y MANUAL: N where Y and N indicates a yes or no response to the prompt. If you are set up for 1200 baud communications, the list will show HIGH SPEED: Y. You can also see that the modem is currently programmed to dial any phone number entered using pulse signaling (PULSE DIAL: Y) at a slow dialing rate (SLOW DIAL: Y). (See page 23 for the List Command, under PROGRAMMING COMMANDS, for a complete discussion of the modem's parameters. After the parameters are listed, the modem returns to the COMMAND RECEPTIVE STATE (off-line status) where it waits for further instructions. LOG ON COMPUSERVE INFORMATION SERVICE CompuServe Information Service is widely known for its numerous on-line services for both business and home computer owners. Dedicated telephone numbers in major cities provide you access to CompuServe. Use your infor- mation service user's guide to find out how to contact and use the service. Since the modem is already in the command receptive state--waiting for your command--all you have to do to begin the log-on is prepare it to dial the information service access number. For dialing instructions, refer to the D Command under PROGRAMMING COMMANDS for the valid dialing codes, page 27. 1. Press to place the modem in the dialer programming mode. EXAMPLE: If you enter 1(111)555-1234 as your local 1200 baud access number, the sequence appears as: D1(111)555-1234 2. When the phone number is properly formatted, press to force the modem to seize the telephone lines and to begin dialing the number. OFF-HOOK (OH) indicator lights. The screen shows DIALING...., then the number string that was dialed. 3. When the ringing stops, the modem sends the message: ON LINE ORIGINATE Other line conditions (BUSY,DEAD LINE, NO TONE) that can be detected by the modem are discussed in AUTOMATIC MODE OPERATIONS, page 17. 4. Press (break character C^ appears) and type the User ID number that you received with the software package when the screen prompts: USER ID: 5. Next, type the password that you received with the software package when the prompt appears: PASSWORD: Your password is not printed on the screen to retain its secrecy. At this point, your log on the CompuServe is complete and you may begin using the service. To use other information services and host systems, simply substitute the appropriate dialog as provided in the information service user's guide. ANSWER OR ORIGINATE A CALL AUTOMATICALLY When communications is completed with the information service, the modem reverts into the disconnect mode. To program the modem to resume monitoring the telephone lines for incoming calls, enter: <*> <.> Wake up. Select originate mode. Do it!!! OH INDICATOR LIGHTS. The modem seizes the phone lines and begins dialing the access number that you used earlier. Remember, any number entered in dialer memory will remain intact until a new number is entered or the modem is turned off. When the call is completed, the modem goes back off-line and communications ends with the DISCONNECT prompt. Answering and origination calls automatically is discussed in more detail under AUTOMATIC MODE OPERATIONS, page 15. CHANGE ADVANCED PROGRAMMING OPTIONS The DC-2212 modem is equipped to perform many operations that are equivalent to the functions of an operator making a call. When the modem detects a busy signal after dialing a number, the message BUSY is printed on the screen. (DC-2212 enters the disconnect mode.) In a similar situation, a telephone operator might say: "I'm sorry, that number is busy. Would you like to place the call again later?" You would hang up the receiver, wait about 30 minutes, and try to make the call again. With the modem programmed to redial a number found busy, the second attempt is made after a 60-second delay. When a busy signal is received, the cycle--disconnect, wait, redial, disconnect, wait,...--continues until the number of programmed attempts is completed, or you abort the process with the * command. To change the defaulted dial attempts setting or any of the advanced para- meter settings, follow these steps: <*> <.> Wake up. Bring the advanced programming options to the screen. 1. Press . The DIAL ATTEMPTS prompt appears on the screen. DIAL ATTEMPTS: 1? 2. Change the defaulted number to a value other than 1 by typing in that new number. Press (five times) until you have exited the menu. 3. Press , enter the phone number to be dialed, and press . Other automatic operations that you can control through the advanced programming command (ICommand) are explained in PROGRAMMING COMMANDS, page 31. MANUAL MODE OPERATION When operating in manual mode, you can control the system by manually dial- ing and answering the telephone. Manual mode (answer or originate) is useful when you want to talk by telephone to a friend on the other side of town, and later, exchange computer data without redialing. EXAMPLE: The phone rings and you answer by picking up the receiver. After talking awhile to a friend, you decide to exchange information by computer (telecommunications)-- without breaking voice call./ 1. Your friend selects to be the originate station, while you are the answer station. Set up your modem by entering: <*> <.> Wake up. Select manual mode. Select answer mode. 2. Give your friend time to set up the originate modem by entering <*><.>. You may recall that automatic originate mode is a preset condition at initial power-up. 3. When you near the originate modem's carrier tone (a high-pitched sound), press . Your modem seizes the line and lets you know that communicat- ions can take place by sending the message ON LINE ANSWER. 4. The answer station ALWAYS issues the X command first. After hearing the answer modem's carrier tone, the originate station sends the X command to make the connection and the screen prompts ON LINE ORIGINATE. Be sure to keep quiet when the handset is off-hook. Noise picked up could cause errors in the data being passed by the modems. After the data has been successfully transmitted, the modem sends the mess- age DISCONNECT. Be careful when you hang up the telephone since slamming or dropping the phone back on the hook while the modems are controlling the lines could disrupt carrier long enough to start a loss-of-carrier dis- connect sequence. TO RETURN TO VOICE COMMUNICATIONS AFTER TRANSMITTING DATA: 1. Carefully pick up the receiver (both modems). 2. Type at the keyboard that you will be aborting carrier. For example, you might signal your friend by entering: THAT'S ALL THERE IS FOR NOW. I AM ABORTING CARRIER. 3. After making sure your handset is off-hook, enter the abort character sequence (see page 21, "TRANSMISSION OF THE ABORT CHARACTER") to force the modem off line. For Model II, 12, and 16 users, this sequence is CONTROL T. Press . After 3 seconds of inactivity, your modem logs out with the disconnect prompt and your friend's modem (if automatic) shuts down, too. TRS-XENIX OPERATION Your DC-2212 modem is configured to operate with a TRS-XENIX Operating System (Version 1.3.2 or later). This section will be helpful in explain- ing how using the DC-2212 with TRS-XENIX differs from operations in other modes. When you are ready to use the modem with TRS-XENIX, you should be familiar with the following functions: enable logins, disable logins, and dial out. To access TRS-XENIX, you must log in as the super-user --or "root"--and tell the system which serial channel (A or B) you plan to use. For example, enable a channel by typing: ENABLE TTYO1 ENABLE CHANNEL A or ENABLE TTY02 ENABLE CHANNEL B The serial channel that is used must be disabled before using the cu command for making a call (originate mode) or "dial out." To disable a channel (A or B), type: DISABLE TTY01 or DISABLE TTY02 TO OPERATE IN AUTOMATIC ANSWER MODE: Set the AUTO-ANSWER switch, located on the modem's rear panel, to the posit- ion nearest the DB-25 jack and power up the DC-2212. From a power-on condit- ion, the DC-2212 will power up into the call-waiting state and monitor the telephone line for an incoming call. When the DTR is asserted (this happens when the logins are allowed using the enable command), the modem will pick up the call and assume auto-answer, 10-bit word, 1200 baud operation. NOTE: This switch is only read (active) when power is freshly applied to a DC-2212 operating TRS-XENIX. Be sure you turn the modem's power OFF, then ON again, whenever you change the position of the switch. DIAL OUT Set the AUTO-ANSWER switch on the modem's rear panel to the position nearest the DB-25 jack, and power up the DC-2212. Program the modem to automatically dial a call by entering the cu command: cu phone number -s 1200 where phone number is the number you want dialed and the -s value is the baud rate selected. To dial the call out on Channel B, type: cu phone number -s 1200 -a/dev/cul1 When the prompt CONNECTED appears, you an begin communications. See your TRS-XENIX system's documentation for more information on using a modem with TRS-XENIX. NOTE: cu will assume tone dialing. If your phone system requires pulse (rotary) dialing, insert "r" before entering the phone number. WAKE UP, DC-2212! At the initial power-up--after breaking connection with the telephone lines--the modem enters an off-line (or waiting) mode and remains in this mode until you tell (command) it what to do next. The WAKE-UP command is the only command the DC-2212 modem responds to while in the off-line mode (from power-up). It is the AUTO-BAUD-RATE-DETECT CODE SEQUENCE which forces the modem from the off-line status into the command receptive state. To send this command from your computer or terminal key- board, press <*> <.>. The screen echoes *. You may have noticed that the * was not echoed until you pressed <.>, the second key in the auto-baud-rate detect code sequence. That's because both keys are needed to determine the baud rate, bit count, and parity (if any) you are using at your computer or terminal. When the correct baud rate is detected, this character * (2A,in hex code) is output. SWITCHING FROM HIGH TO LOW BAUD OPERATION The DC-2212 modem automatically synchronizes with standard 75,110,150,300, 600, and 1200 baud rates. Switching from a high speed (1200 baud) to a low speed (300 baud) operation occurs when you wake up the modem. If the wake up code sequence detects a 1200 baud rate, the modem communicates in high speed. If it is awakened at 300 baud, low speed operation is used. What happens if you wake up the modem in low speed mode, but want to call a high speed modem? If that modem has low speed detection circuitry, it selects 300 baud operation. If it can not shift baud rates, the originating modem must change its operation. The originating station always determines the speed of operation when one DC-2212 modem calls another DC-2212 modem. ENTERING COMMAND RECEPTIVE STATE (CRS) The modem is now in the command receptive state and is waiting for you to begin programming or setting the internal switches that tell it what operations are to be performed. The wake-up command opens the DC-2212 for programming and precedes any com- mand issued while the modem is in the command receptive state. The list of commands that the modem expects to receive are briefly described in Table 1. A detailed description of each command's is provided later in this manual in the section PROGRAMMING COMMANDS. COMMAND FUNCTION L,l List user options/switches A,a Answer mode operation O,o Originate mode operation T,t Tone dialing global command (default) R,r Rotary (pulse) dialing command (default) S,s Slow dialing speed (default) F,f Fast dialing speed Q,q Flag for self-test D,d Dialer programming mode enable @ Refresh abort character M,m Manual/automatic toggle command (automatic default) G,g Forced carrier detect toggle (default) E,e Echo disable/enable command I,i Advanced programming feature enable C,c Clear out all user options X,x Exit command receptive state and execute current switches These commands can be entered in upper or lowercase characters. Seven-bit word and even or odd parity are possible. If parity is set up on your com- puter terminal before you send the wake up command, the modem automatically corrects it parity parameters. Seven-bit words with two-stop bits are also operable. AUTOMATIC MODE OPERATIONS The DC-2212 modem can be programmed to make a call or answer your telephone automatically. In the automatic mode operation, you can call an information service without picking up the phone--just type in the phone number on your computer keyboard. You can also tell the modem to enter the answer mode automatically when the phone-line-ringing is detected. AUTOMATIC ANSWER MODE To program your DC-2212 modem to automatically answer incoming calls: 1. Press <*> <.> to wake up the modem, then press to send the answer command. Remember, if this is a cold start-up, the modem will be defaulted to the automatic originate mode and you will need to press to select the answer mode. (To check that all the parameters are set correctly, press for the list command and look for the ORIG MODE and MANUAL MODE parameters.) The display shows: *A Then, press to force the modem to seize the phone lines. 2. The modem prompts AUTO ANSWER and waits for the telephone to ring. 3. When the phone rings, the modem begins counting the rings as you have programmed (I command, page 31). When the modem answers the line, the computer displays the message: ON LINE ANSWER. When carrier is asserted by your modem, the calling modem replies with its carrier. The modems are now in an on-line status and telecommunications can begin. If the modem does not receive a valid tone from the other modem within 13 seconds, it aborts the call with the statement NO TONE (no carrier tone). The DC-2212 modem then reverts back into the auto-answer and outputs AUTO ANSWER to your computer. When either modem breaks connection after a successful data exchange, the DC-2212 alerts you by sending thee message DISCONNECT and returns to the auto-answer mode and monitors the lines. As long as the modem is in the auto-answer mode, it will continue to monitor the telephone lines for an incoming call. Regardless of the number of calls received and the number of calls that transferred computer data to your system, the DC-2212 modem always returns to the call-waiting state. You can turn off this call-waiting mode by press- ing <*> (<.> is not needed). When the modem sees the * (* will not be echoed), it will return to the command receptive state. NOTE: The parameters are still not changed! If you want to return to the auto-answer mode, send the X command. If you want to make an outside call, press (originate mode) to take the modem out of the answer mode. AUTOMATIC ORIGINATE MODE When you want to call another modem, but do not want to dial it yourself, you can program the modem to dial it in the auto-originate mode. 1. Press <*> <.> to wake up the modem. When cold-started, the modem defaults to automatic originate mode. Press to check them modem's current parameters. These commands echo as: *L If your listing does not show MANUAL MODE:N and ORIG MODE:Y, press . 2. Use the D command to program the dialer memory,--that is, tell the modem what number you want dialed. After typing in the phone number, press X to force the modem out of the command receptive state and to begin dialing the number (See dialing instructions and codes under PROGRAMMING COMMANDS, page 27.) 3. When the X command is received, the DC-2212 outputs a carriage return and line feed. Then, it seizes the telephone line and outputs to the computer: DIALING... Each number dialed is flashed on your screen in the sequence and speed specified. The modem must detect a dial tone before it begins signaling the telephone line. See signaling rates, under PROGRAMMING COMMANDS, pages 25-26. 4. When the carrier tone is heard, the modem sends the message: ON LINE ORIGINATE When the DC-2212 modem reaches the end of its programmed dialer memory, another carriage return/line feed is issued and the modem's line status circuitry checks the progress of the call made. Actually, the modem has used part of its line status capability when it first made sure there was a valid dial tone on the line before it started dialing. See LINE STATUS CONDITIONS to find out the line conditions that can be detected by the modem. LINE STATUS CONDITIONS After a number has been successfully dialed, one of the four status condit- ions results: 1. Modem hears ring-back--ringing of phone called. Sweet success! 2. Modem hears nothing! Ooops! 3. Modem hears a busy signal. Darnit! 4. Modem hears a re-order signal. Oh, oh! LINE CONDITION 1--RING-BACK When the modem hears the phone ring, the message RINGING...is displayed. Each ring cycle detected by the modem is counted until the ringing stops. The count stops when the telephone receiver is picked up or if the modem is programmed (I command, advanced programming feature) to abort a call that is not answered on a designated number of rings. When the ringing stops, the modem assumes the call is complete and outputs the message ON LINE ORIGINATE (if you did not use the A command in the dialer program). As soon as the carrier tone is received from the called modem, you can begin communications. You are now in the on-line mode. LINE CONDITION 2--NO SOUND When nothing happens after a number is dialed, check the number that you stored in the dialer memory. Or, maybe the problem is within the telephone company. The modem will wait for about 50 seconds before aborting a call. The message DEAD LINE is displayed. The modem returns to an off-line status and enters the waiting state. Send the wake-up command to enter the command receptive state. LINE CONDITION 3--BUSY SIGNAL The message BUSY appears on your display when a busy signal is detected. The modem disconnects itself from the telephone lines and returns to the off- line waiting state until it receives the wake-up command. If the DIAL ATTEMPTS parameter of the modem is programmed for a number other than 1 (the defaulted number), the busy redial sequence is activated. Therefore, after the first attempt, the modem will automatically wait for about 60 seconds, then it will seize the line, look for a dial tone, dial the number, and monitor the progress of the call. WHAT HAPPENS IF THE LINE IS STILL BUSY ON THE SECOND ATTEMPT? Well, DC-2212 hangs up and starts the process again. If the modem is programmed for two dial attempts and has tried twice, but failed to complete thee call, everything stops here and the modem enters the off-line state. If programmed for more than two dial attempts, the modem waits for 60 seconds and tries again. The modem will keep trying until the attempts count is completed, or until the call is completed. When completed, the message ON-LINE ORIGINATE is printed to the display. LINE CONDITION 4--RE-ORDER TONE The re-order tone is a beeping tone the telephone company uses to tell you that something is wrong. Either your modem's numeric data was not valid, you dialed too fast, or, for some reason, the company can't process your call. Since the DC-2212 can not distinguish a re-order tone from a dial tone, it will wait the full time-out before it stops looking for a carrier condition. DIAL SEQUENCE EMERGENCY SHUTDOWN COMMAND When you discover that the modem is dialing an incorrect telephone number, or you don't want to wait for the time to expire, you can turn off the dial sequence. Press any key after the X command is issued and before ON LINE ORIGINATE is displayed on the screen. This will shut down the dialer and return the message DISCONNECT. BUSY NUMBER REDIAL INTERRUPTION While the modem is in the 60-second timer delay (before making another attempt to redial a number found busy), you can interrupt the process by using the <*> <.> wake-up sequence. The wake-up command forces the modem into the command receptive state and aborts the busy redial mode. ABORTING ON-LINE MODES There are four conditions which will abort an on-line status while you are in communications over the telephone lines. 1. LOSS OF CARRIER 2. LOSS OF DATA TERMINAL READY (DTR) 3. RECEPTION OF A LONG SPACE 4. TRANSMISSION OF THE ABORT CHARACTER CONDITION 1--LOSS OF CARRIER The carrier is the sound you hear if you pick up the receiver while the DC-2212 is in communications with another modem. If you are operating at low speed (less than 1200 baud), the carrier sounds like a steady, pure tone. You will be able to hear a change in the pitch of the tone if you type on the keyboard. During high speed operations (1200 baud), the carrier sounds like running water, or static. Regardless of the speed of operation, the tone (or noise) is the carrier signal. When the carrier signal is detected, the CD indicator lights on the front panel. If the carrier is interrupted longer than 300 milliseconds, the modem will begin the disconnect sequence. The message DISCONNECT is dis- played on your screen and the modem goes into the off-line state. A "loss of carrier" disconnect can result other than from being turned off by one of the modems. If you drop the receiver back onto the telephone cradle, or shout into the handset, the noise generated may be strong enough to MASK the carrier so that the DC-2212 thinks carrier is turned off. Although the low speed carrier is less susceptible to noise than the high speed carrier, there is always the possibility of data errors. CONDITION 2--LOSS OF DATA TERMINAL READY (DTR) Data Terminal Ready is a protocol signal that the DC-2212 receives from your computer or terminal. It must be true (asserted) before any modem operation is allowed. If you get to this point (on-line mode), carrier has been asserted. DTR is defaulted ON in the DC-2212. Therefore, if your computer does not have a DTR control wire, the modem will make sure this signal is set up. Of course, if your cable connection is incorrect and the DTR pin at the modem is shorted out, you will not be able to get the modem to talk. On computers with DTR control, you can stop any function by forcing the signal to disassert. Beware of the accidental DTR switch off! For example, if you decide to change a terminal feature (i.e., turn on a printer port) while you are communicating with a time sharing service,, you could switch your terminal software around to its utilities menu and, suddenly, the DC-2212 could drop its telephone connection! Some terminal (and software) systems turn off DTR when the system is doing utilities work. CONDITION 3--RECEPTION OF A LONG SPACE The serial data going to the DC-2212 over the RS-232C cable is normally in a marking state. When you press a key, a start bit is transmitted (the serial line goes spacing) for a time depending on the baud rate you are using. The bits which make up the word are then serially shipped to the modem, one-by-one. These bits are marking or spacing levels, depending on the type of bit (1 or 0). The last bit to be transmitted is the stop bit and it is always a marking level. A long space is a start bit that takes anywhere from a half to one full second to end. It is not a character, although some systems consider it to be the null (0) word with a framing error (it lasted too long before the stop bit happened along.) The long space is an old method that teletype machines used to say: "Hey, you! Pay attention to me!!!" Several long spaces can be strung together by multiple closures of a key (usually ). This string of spaces can tell a modern day modem: "I'm all done, Go ahead and turn off." The long space method of disconnecting a modem from the lines is known as a long space disconnect sequence. If DC-2212 receives a long space from the host computer which lasts 1.5 seconds or longer, it will go into the off-line mode and disconnect from the telephone lines. Remember, you can turn this feature off with the I command parameters. CONDITION 4--TRANSMISSION OF THE ABORT CHARACTER The abort character disconnect feature enables you to disconnect an on-line DC-2212 without having to remember about long spaces or shouting into the telephone. The abort character can be used in the following manner: If you transmit (and type) the abort character and do not transmit any other character for three seconds, the modem will disconnect from the telephone lines. The abort character can be turned off by typing any key within that three-second period. The I command parameters are set up to allow you to disable the abort character disconnect feature. The abort character (when sent) uses long space disconnect signaling to tell the other end of the line that your modem is about to shut down. This long space signaling is only true if you have not disabled transmission of long space with the I command parameters. (dtc-08/04/93)