AUTODIALER USER`S MANUAL - J
Contents
1. J Tech Engineering Ltd GC 11080 Bond Boulevard Delta BC V4E 1M7 Canada Tel 604 543 6272 Fax 604 543 6476 engineering Itd http www jtecheng com AUTODIALER USER S MANUAL REVISION HISTORY 07 05 03 Initial Release 04 03 04 Removed unneeded sections 26 10 05 Added information in support of alternate baud rates TABLE OF CONTENTS U NE ooien RE 2 RG Oe VTT 2 3 HARDWARE DESCRIPTION aunime daenna EEEN AEE AAE EEA EEE AEAEE EA AA E EE AEEA 3 dk SYSTEM GONFIGURATION a sesasine dinean aa ea aa a EOE a aE e KE ee AEA AE a aE 4 LIST OF TABLES TABLE 1 INDICATOR DESCRIPTION 00ecececececececececesececececaceeacecacecacaeaeaeaeaeaeacaeaeaeanaeaeauanaeauaeanananananananananananaes 4 LIST OF FIGURES FIGURE 1 TIMING DIAGRAM ssososssssesesssessssssessersnurururururururunututt eteten nton nE eE nE PEREPERE SERERE REEERE REEERE EEEE S EEE EREEREER E Ennen 3 FIGURE 2 TERMINAL EMULATION DETTINGS 4 FIGURE 3 PORT AND TERMINAL EMULATION SETTINGS 0 0000ccccececeeeseeeseseeesesecseeeeeeeeeeeeeseeeeeeeseseeseeseeeeeseeeeeeees 5 FIGURE 4 ASCII CONFIGURATION 0ccccceeesesesesesececseeceeeceeececeeececeeeseeeeecseeseeeceeeseeeeeceeeeeseteeeeeeseeseeeseeeeeeseeeeees 5 FIGURE 5 CONFIGURING THE AUTODIALER WITH HYPERTERMINAL 0c0c0s0seseeeeeseseseseceseeeseeeeeeseeeeeeeeseeeeeeeeeeeees 6 Autodialer User s Manual Date 27 10 05 8 36 AM Doc ADLR UM 2005 J Tech Engineering LTD Page 1 of 6 1 INTRODUCTIO2. N The Autodialer has been designed to add dial out capability to a device not capable of generating AT dialing commands Successful operation of the Autodialer requires the following conditions be met e The device originating the call is capable of asserting a signaling lead i e RTS radio PTT etc before sending a message e The device originating the call has a message re send facility with configurable number of and time delay between retry attempts e Either the modem or the far end equipment is able to drop the link The Autodialer is placed in line between the DTE device and the modem Connectors are standard EIA 232 9 pin dSUBs The Autodialer will not interfere with RX data from the modem or DTR DSR and RI signaling leads The Autodialer will block TX data from the DTE device to the modem when no connection is established RTS and CTS signaling leads are passed through when a connection is made 2 SYSTEM OVERVIEW All settings in the system should be carefully reviewed before any decisions are made System performance should be evaluated for bad and worst case scenarios Getting the Autodialer to work when the far end answers immediately and a connection is established quickly is relatively simple The true test is to have an unsolicited message report when the first few connection attempts are unsuccessful As an example consider implementing the Autodialer in a land line dial up scheme When the DTE device has data to se
3. ecovery from unforeseen software lockups Switch SW2 provides manual initiation of a TX dial string and in combination with SW1 is used to enter programming mode Three LEDs are provided for visual indication of the state of the Autodialer The STATUS LED indicates that the microcontroller is running properly It flashes at a rate of 0 5 Hz when the Autodialer is idle and 5 Hz when the Autodialer is establishing a connection When a connection is established the STATUS LED will continue to flash at 5 Hz plus the LINK LED will come on The DTE RTS LED indicates the status of the DTE RTS signaling lead Rev12 sss Autodialer User s Manual Date 27 10 05 8 36 AM Doc ADLR UM 2005 J Tech Engineering LTD Page 3 of 6 Table 1 Indicator Description STATUS Indicates the current operating state of the Autodialer DTE RTS GREEN Indicates transmission activity during normal operation LINK YELLOW Indicates if a link has been established with the remote modem 4 SYSTEM CONFIGURATION To enter configuration mode hold down the Test button SW2 while resetting press and release SW1 or powering up the Autodialer Programming features through terminal emulation software requires the following three conditions be met 1 Jumper JP1 is installed 2 Nothing is plugged into the modem port J3 3 A standard serial port cable is connected from J2 to a host PC If an RS 232 port is not available as is the trend with notebook com
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5. imeout 1 255 seconds 30 Speed SKS 110 4 1200 7 9600 2 300 5 2400 8 14400 3 600 6 4800 9 19200 Choice 7 Enter Dial String Max 31 digits atdt1800 657923 Write to Memory y Changes Saved restarting atdt18007657923 Connected 0 48 20 Auto detect 9600 8 N 1 SCROLL CAPS NUM Capture Print echo Figure 5 Configuring the Autodialer with Hyperterminal Pressing lt enter gt without any data present will retain previously saved settings Connection time out is specified in seconds with the minimum being one second Entering a value of zero will result in one second any value over 255 will result in a 255 second connection timeout Communication speed is chosen by selecting a number from the table listed after Speed bps Do not enter the actual desired baud rate i e Do not type 9600 for 9600 bps simply press 7 followed by lt enter gt After programming press the TEST button SW 2 to display the configured dial string Note that the LINK LED on the Autodialer will flicker while the microprocessor is receiving data Configuration changes are stored in EEPROM memory along with a checksum to indicate if the data is valid The message EE write Fail will be displayed if written data does not match the checksum If this message re occurs it likely indicates a faulty microprocessor Rev12 sss Autodialer User s Manual Date 27 10 05 8 36 AM Doc ADLR UM 2005 J Tech Engineerin
6. nd it calls the master station waits for a connection indicated by DCD and transmits data once the connection has been made If a connection cannot be made the device hangs up the modem waits a set amount of time and redials After a number of redial attempts the device gives up as its data is no longer useful or current In the above example the DTE device does not have the ability generate a dial string wait for DCD before transmitting data or hang up the modem A typical configuration is as follows DTE device data transmit retries are set to three with a retry interval of 20 seconds Autodialer connection timeout is set to 45 seconds Ideally the operation would be as follows Dialing is initiated when the DTE device asserts RTS The Autodialer blocks any data coming from the DTE device and sends the dial string to the modem The DTE s second attempt at sending data 20 seconds later is also blocked as a connection has not yet been established Twenty five seconds later a connection is finally made The Autodialer will now pass TX data from the DTE device The master and slave communicate on the second retry attempt After 60 seconds of idle time the master hangs up the remote modem causing the local modem to detect loss of carrier and disconnect Now consider what would happen if the DTE device s second retry attempt failed The Autodialer times out at 45 seconds During this time the DTE device has attempted to transmit da
7. o give up a call attempt at 45 seconds In the event that the modem at the far end answers but does not connect properly the master end should be configured to hang up after 60 seconds This will still allow three redial attempts in most cases Times can be adjusted as required however the above sequence works well for most situations Modems should be configured to disconnect if no data has been sent for a time longer than the total time duration of Figure 3 This will help avoid the situation of the remote modem being powered up and connected to the phone line and the master end device disconnected or not generating hang up commands The link may otherwise stay connected indefinitely On power up or device reset the Autodialer sends a carriage return to the modem to clear the modem s input buffer 3 HARDWARE DESCRIPTION The power supply input voltage should be in the range of 8 28 Voc No SWC protection is provided the Autodialer should be powered from a protected DC source The Autodialer does not provide electrical isolation between the EIA232 ports and the applied DC power source This should be considered when selecting the source of power EIA232 transceiver is not capable of providing power to port powered isolators All data inputs and outputs are protected against static discharge and HV transients Switch SW1 provides reset of the microcontroller without power down The microcontroller has an in built watchdog timer to allow r
8. puters a USB RS 232 adapter may be used as a substitute Although Hyperterminal is used in the following example any terminal program can be used for this purpose Typical settings for Hyperterminal are as follows autodialer Properties 29 x Connect To Settings l m Function arrow and ctrl keys act as Gi C Windows keys Backspace key sends e Da C Del C Ch Space Ctrl H Emulation auto detect x Telnet terminal fansi Backscroll buffer lines E I Beep three times when connecting or disconnecting ASCII Setup Jemna Setups Figure 2 Terminal Emulation Settings Autodialer User s Manual Date 27 10 05 8 36 AM Doc ADLR UM 2005 J Tech Engineering LTD Page 4 of 6 COM1 Properties ee ee Figure 3 Port and Terminal Emulation Settings The factory speed setting for the Autodialer is 9 600 bps with 8 bits of data no parity and one 1 stop bit as reflected above in Figure 3 If the Autodialer s speed Bits per second is adjusted to a different speed the Hyperterminal program must be configured to match the new speed setting ASCII Setup x x Figure 4 ASCII Configuration Rev12 sss Autodialer User s Manual Date 27 10 05 8 36 AM LE erem ADLR UM 2005 J Tech Engineering LTD Page 5 of 6 e autodialer HyperTerminal iol x File Edit Yiew Call Transfer Help J Tech Engineering Ltd Autodialer Mark Enter DCD Wait T
9. ta three times The Autodialer may establish a connection on its second attempt but the DTE device no longer attempts to send data The above example shows that retries will need to be a minimum of one for any chance of successful data transmission In reality one retry is lost on every dial attempt Rev12 sss Autodialer User s Manual Date 27 10 05 8 36 AM Doc ADLR UM 2005 J Tech Engineering LTD Page 2 of 6 A typical sequence is shown in Figure 3 For illustration purposes a connection is never successfully made 1st Attempt Retry 1 Retry 2 Retry 3 Retry 4 Retry 5 Retry 6 Retry 7 Retry 8 t 0S t 20S t 40S t 60S t 80S t 100S t 120S t 140S t 160S Dial Attempt 1 Dial Attempt 2 Dial Attempt 3 K D Dead time while Zone where connection Connection will have been connection is has likely been made or call dropped One retry established established First retry scheduled in case of long connect should occur here time or second attempt was corrupt Figure 1 Timing Diagram To correct the problems of the previous example DTE device data transmit retries should be set to eight retry interval to 30 seconds and Autodialer connection timeout should be set to 70 seconds The result is two data transmission attempts per dial attempt and three dial attempts in total Four minutes elapses between the first and last attempt Note that the modem should be configured t
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