COURIER HST CHAPTER 5 INTERNAL CONTROLS The commands explained in this chapter are of two types. The first group concerns default configurations, for example, writing your own power-on defaults to nonvolatile random access memory (NRAM). The remaining commands are used to select the modem's local operating characteristics, for a current session or to include in your default configuration. They include result code, echoing, and other options. NOTE: When you change a default setting during a session, the modem retains that setting until you do one of the following: o Select a new setting. o Issue the ATZ command to reset the modem to its software defaults. If DIP switch 10 is OFF, the modem resets to the defaults stored in nonvolatile memory (NRAM). If DIP switch 10 is ON, the modem resets to the factory settings stored in read-only memory (ROM). Issuing the AT&F command resets the modem to its factory settings. o Turn the modem off. SETTING/USING DEFAULTS The Courier HST is shipped from the factory with its software defaults stored in read only memory (ROM) and also in programmable nonvolatile random access memory (NRAM). The inclusion of NRAM allows you to program your own configuration and save the settings as your power-on defaults. Writing Defaults to NRAM (&W) If you store your own default software settings in NRAM, the Courier loads those settings when it is powered on if DIP switch 10 is UP (factory setting). A list of the settings stored in NRAM is in Appendix B-4. You can also display the settings at any time by selecting option 5 of the I (inquiry) command: ATI5 If you've sent the modem commands to change settings throughout your session and want to save your current configuration, issue the &W command: AT&W 5-1 COURIER HST You can also specify your configuration in a single command string that includes the &W command, as in this example: AT X4 &B1 &M5 &H1 &I1 M3 &W 5-2 COURIER HST Modify one or several settings at any time, for example: AT X7 &W Loading the Factory Defaults (&F) Factory defaults are permanently stored in read only memory (ROM). They are listed in the table of NRAM settings in Appendix B-4. You can set the modem to its factory defaults during any session by typing: AT&F If DIP switch 10 is DOWN, the factory settings are loaded at power on instead of the NRAM defaults. Resetting to NRAM Defaults (Z) If DIP switch 10 is UP, reset the modem to its NRAM defaults by typing the following command: ATZ NOTE: On reset, the modem also checks the status of DIP switches 2-5 and 9: if you change the setting of any of these switches when the modem is on, use the Z command to initiate the new setting(s). Storing Telephone Numbers (&Zn=s) The modem stores up to four frequently called phone numbers. Write the numbers to NRAM with the &Zn=s command, where n is position 0 through 3, and s is the number-string. The number-string may be up to 36 characters long, including any Dial command options. The following example includes the tone- dial (T) and comma pause options of the Dial command. The number is stored at position 0, assumed because there is no n parameter. AT&Z=T9,,5551234 The next example stores the phone number and user's access code for a long distance phone service. AT&Z1=5551234,,9876,, Dial the stored number using the DSn command, for example, DS2 . Additional examples are in Chapter 6. NOTE: Don't include modem settings in the &Z string. If the call requires a special setting, insert the appropriate command when you dial the stored number. In the following example, &M0 5-3 COURIER HST (no error control) is substituted for the user's error control default setting: AT&M0DS2 Then reset the error control mode after the call, for example: AT&M4 RESULT CODES Four commands control the result codes the modem returns to the screen: Vn Numeric/verbal response mode Xn Result code subset Qn Display/suppress all result codes &An Display/suppress /ARQ result codes Response Modes (Vn) Result codes are sent to the screen in either words (Verbal Mode) or numbers (Numeric Mode). The Courier is factory set to verbal messages when it is powered on (DIP switch 2 is UP). Use the V command to select verbal/numeric result codes independently of the switch setting. V0 Numeric Mode. Numeric result codes are followed by a Carriage Return but no Line Feed, as in the following example, where a 3 is returned (for NO CARRIER). ATD1234567 becomes 3TD1234567 V1 Verbal Mode. Verbal responses are preceded and followed by a Carriage Return and a Line Feed, as in the following example: ATD1234567 NO CARRIER Result Code Sets The format of the command to select a result code set is ATXn, where n is a value from 0 through 7: X0 Basic subset, returns the first five codes (0-4) in the following table. X1 Extended subset, codes 0-5, 10 and 13. Default. This set adds rate-specific CONNECT messages to the Basic set. 5-4 COURIER HST X2-7 These options offer advanced call-progress codes and functions. RESULT CODES OPTIONS TABLE Commands X0 X1 X2 X3 X4 X5 X6 X7 Result Codes 0/OK X X X X X X X X 1/CONNECT X X X X X X X X 2/RING X X X X X X X X 3/NO CARRIER X X X X X X X X 4/ERROR X X X X X X X X 5/CONNECT 1200 X X X X X X X 6/NO DIAL TONE X X X X 7/BUSY X X X X X 8/NO ANSWER X X X X X 9/Reserved for future use 10/CONNECT 2400 X X X X X X X 11/RINGING X X X 12/VOICE X X 13/CONNECT 9600 X X X X X X X Functions Adaptive Dialing X X X X X X Wait for 2nd Dial Tone (W) X X X X X Wait for Answer (@) X X X X X Fast Dial X X X X Options Summary 1. An additional group of CONNECT messages (15-17) indicates an error-control connection with an HST- or MNP-compatible modem. See /ARQ Result Codes (&An) later in this section. 2. Adaptive dialing causes the modem to automatically use Touch-Tone dialing and, if that doesn't work on the line, revert to pulse dialing. 3. W and @ are Dial options described in Chapter 6. 4. Fast dial causes the modem to dial as soon as a dial tone is detected, rather than wait the normal two seconds. If there is no dial tone, the modem times out after 5 seconds and sends the NO DIAL TONE (6) result. 5. After sending the BUSY (7) result code, the modem hangs up. 6. The NO ANSWER (8) result code is returned, instead of the standard NO CARRIER, when the @ option is used and there is no answer at the remote end. 5-5 COURIER HST 7. After sending the VOICE (12) result code, indicating a voice answer, the modem hangs up. 8. X6 implements all result codes and functions. X7 includes all of X6 except the VOICE (12) result. Quiet Mode (Qn) Enable/suppress the display of result codes. The Courier is shipped with DIP switch 3 DOWN and defaults to display ON when the modem is powered on. The commands here control the display independently of the switch setting. Q0 Result codes are displayed. Q1 Result codes are suppressed (made quiet). This is useful when the messages might interfere with the data stream. /ARQ Result Codes (&An) If these codes are enabled, one of the following results is sent to the screen when a successful HST or MNP connection is established. (A setting of X1 or higher is assumed.) (15) CONNECT 1200/ARQ (16) CONNECT 2400/ARQ (17) CONNECT 9600/ARQ &A0 /ARQ codes are disabled. If your software does not allow the /ARQ result codes, use this setting. Suppression of the /ARQ codes doesn't affect the error control protocol; the modem returns the standard CONNECT messages. &A1 /ARQ codes are displayed. Default. LOCAL ECHO Two commands control what the modem displays on the screen. The En command applies to when the modem is in Command Mode. The Fn command applies to when the modem is online to another system. Command Mode Local Echo (En) The En command enables/disables the display of your typed commands. If double characters appear on the screen, both the modem's local echo and the software's local echo are on. The Courier is shipped with DIP switch 4 UP, for local echo ON when the modem is powered on. The commands here control the echo independently of the switch setting. E0 Command Mode echo OFF. The modem does not display keyboard commands. E1 Command Mode echo ON. 5-6 COURIER HST Online Local Echo (Fn) This command causes the modem to display a copy of the data it is transmitting to another system. Many systems, however, return a copy of received data, which is called a remote echo. If the modem's online echo is ON and there is remote echoing, double characters appear on the screen. In some microcomputer documentation the online echo setting is called the "Duplex" setting, although the term is not technically accurate. F0 Online echo ON. Sometimes called Half Duplex. As the modem transmits data to a remote system, it also sends a copy of the data to the screen. F1 Online echo OFF. Sometimes called Full Duplex. This is the default. THE AUDIO MONITOR The modem's speaker enables you to monitor the dial-connect process. There are several ways to make use of this feature. After the Courier 2400 dials a number, it waits 30 seconds for a high-pitched answer tone from the other modem, immediately followed by data signals, called a carrier. These signals must occur before a data link is established. If someone answers the phone, or if the line is busy, the modem sends the message NO CARRIER to your screen after 30 seconds. If you listen to the speaker, you can respond immediately instead of waiting for the modem to time out. For example, if you hear someone answering the call, you might pick up the phone and talk to the person or cancel the call by pressing any key on the keyboard. In the same way, you can cancel a call when you hear a busy signal. You can also hear if dialing is proceeding too fast for the system. Terminate the call (press any key) and reenter the Dial command with a comma or two to allow more time. This applies to accessing an outside line (dialing 9, for example) as well as to checking out whether a public service has enough time to respond to your account number or other code. Speaker Control (Mn) You can disable the speaker entirely or set the speaker to monitor different segments of the dial-connect sequence. M0 The command ATM0 turns the speaker OFF entirely so that you don't hear the modem go off hook, dial, etc. 5-7 COURIER HST M1 The speaker is ON until Carrier Detect. Default. You can monitor call progress until the Courier detects the remote modem's carrier signals, or until the 30-second timeout and result code display. At Carrier Detect, the modem disconnects the speaker and data transmission sounds are suppressed. M2 The speaker is ON continuously, including during data transmission. M3 The speaker doesn't go ON until after the last digit is dialed, then goes OFF at Carrier Detect. MODEM CLOCK USAGE (Kn) The modem clock is used as a call-duration timer or as a real- time clock. Used in conjunction with the In (Inquiry) command, the modem returns the duration of the last call in hours, minutes, and seconds or the actual time. K0 Call-Duration Mode. Default. The modem times each call from CONNECT to NO CARRIER, and stores the information until the next connection or the modem is reset. At ATI3 , the modem displays the call's duration. If you wish, you can maintain a call log by printing this information after each call. K1 Real-Time Mode, The clock operates as a real-time clock regardless of the presence of a carrier. Set the clock (military time) by specifying the hour, minutes, and seconds as in the following example, which sets the clock at the real time of 1:30 p.m. ATI3=13:30:00 K1 At ATI3, the modem displays the real time. You'll need to set the clock each time you power on the modem, but the clock is not affected by the reset command, ATZ. TRANSMITTER ENABLE/DISABLE (Cn) If an additional terminal and modem share the phone line for monitoring purposes, the second modem is placed in Receive Only state by disabling its transmitter. C0 Transmitter disabled. Modem is set to Receive Only. C1 Transmitter enabled. Default. BREAK HANDLING (&Yn) The Courier HST allows you to send a break to abort data transfer without disconnecting from the data link. The following options are available. 5-8 COURIER HST NOTE: A destructive Break to the modem resets its data compression tables. The remote modem also resets its data compression tables. &Y0 Destructive, no Break transmitted: the modem clears the data from its transmit buffer (all data is lost) but does not pass on the Break to the remote modem. &Y1 Destructive, expedited: the modem clears the buffer and immediately sends a Break to the remote modem. This is the default setting. &Y2 Nondestructive, expedited: the modem retains buffer data, but immediately sends a Break to the remote modem. &Y3 Nondestructive, unexpedited (send Break in sequence): the modem transmits any buffer data received before the Break, sends the Break, and then sends any subsequent input from the computer or terminal. THE S-REGISTERS The S-Registers are used to set various timing parameters and other operations, including redefinition of selected ASCII characters. The defaults typify the requirements of most users. A detailed summary of the S-Register functions is in Appendix B- 5. Less detailed summaries are on the bottom label of the modem case and in the Quick-Reference card. 5-9