





                                                                COURIER HST


                                                                 APPENDIX F
                                                   TECHNICAL SPECIFICATIONS


          Compatibility       

          USR-HST, 9600 bps, asynchronous, asymmetrical (9600/450 bps with
          automatic handshake adjustment to 300-bps), trellis-coded
          modulation, Quadrature Amplitude Modulation (QAM)

          USR-HST, 7200 bps, asynchronous, asymmetrical (9600/450 bps with
          automatic handshake adjustment to 300-bps), trellis-coded
          modulation, Quadrature Amplitude Modulation (QAM)

          USR-HST, 4800 bps, asynchronous, asymmetrical (9600/450 bps with
          automatic handshake adjustment to 300-bps), unencoded Quadrature
          Amplitude Modulation (QAM)

          CCITT recommendation V.22bis, 2400 bps, asynchronous, Quadrature
          Amplitude Modulation (QAM)

          Bell 212A, 1200 bps, asynchronous, Differential Phase Shift
          Keying (DPSK)

          Bell 103, 300 bps, asynchronous, Frequency Shift Keying (FSK)

          Microcom Networking Protocol (MNP), Service Levels 1-5 at
          2400/1200 bps

          USRobotics proprietary HST protocol at 9600/7200/4800 bps,
          similar to MNP Levels 1-5, adapted for asymmetrical modulation

          RS-232C terminal/modem interface

          Superset of industry standard AT command set, S-registers, DIP
          switches

          Online data rate fallback

          7200, 4800 bps

          Phone Line Interface     

          RJ11, RJ12, RJ13, RJ41, RJ45 phone jacks

          Communications Channel   

          Full/half duplex on 2-wire dial-up, dedicated, or leased phone
          lines, demand-driven high speed channel turnaround



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                                                                COURIER HST


          Data Rates     

          300, 1200, 2400, 4800, 7200, 9600 bits per second

          Operational Modes   

          Auto Dial/Answer, Manual Originate/Answer

          Dialing   

          Rotary (pulse 0-9), Touch-Tone (DTMF 0-9, #, *), a-z when in
          Quote (") Mode

          Data Format    

          Binary, serial, asynchronous; defaults to 7-bit word length, even
          parity

            Start      Data                          Stop
             Bits      Bits          Parity          Bits
              1         7          Even, Odd          1
                                  Mark, Space
              1         7       None, Even, Odd,      2
                                  Mark, Space          
              1         8             None           1, 2
          
          Front Panel Indicators

          HS   High Speed (9600 bps)
          AA   Auto Answer/Answer
          CD   Carrier Detect
          OH   Off Hook
          RD   Receive Data
          SD   Send Data
          TR   Terminal Ready (DTR)
          MR   Modem Ready/Power
          RS   Request to Send
          CS   Clear to Send
          ARQ  Error control connection established
          AL   Analog Loopback Self-Test

          Programmable S-Registers

          Values in parentheses are defaults:

          Number of rings on which to answer (1)
          ASCII character definitions, decimal: escape code (43), Carriage
               Return (13), Line Feed (10), Backspace (8)
          Timing: Wait before dialing (2 sec)
               Carrier Detect wait (30 sec)
               Pause in Dial, Repeat commands (2 sec)

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                                                                COURIER HST


               Remote Carrier Detect before local recognition (0.6 sec)    
               Disconnect at loss of carrier (0.7 sec)
               Escape code guard time (1 sec)
               Touch-Tone duration, spacing (70 Ms)
               Break length, to DTE (100 Ms)
          Disable MNP Levels 3, 4
          Disable 450-bps back channel, force 300 bps
          Optional non-error control Transmit buffer size
          Auto Dial stored phone number on DTR, reset or power on
          Answer in Originate Mode
          Modem self-testing (0, Data Mode)
          Inactivity Timer (0, disabled)
          
          Switch Functions    

          Externally accessible.  Values in parentheses are factory
          settings:  UP = OFF (open), DOWN = ON (closed).

          Volume control
          DTR override (DOWN)
          Result code mode (UP, verbal)
          Result code display (DOWN, displayed)
          Command Mode echo (UP, echo ON)
          Auto Answer (DOWN, AA suppressed)
          CD override (DOWN)
          RJ11/RJ13 jack (UP, RJ11)
          Smart/Dumb mode (DOWN, Smart)
          Online Escape code with/without disconnect (DOWN, no             
               disconnect)
          Load NRAM defaults/ROM factory settings (UP, NRAM)
          RS-232C Modem/Terminal data interface (UP, normal           
               assignments of Pins 2 and 3)
          
          Flow Control Buffers

          Transmit Buffer:

               Error control:  3.5k bytes
               Non-Error control:  1.5k bytes, 128-byte option
          
          Receive Buffer:  2k bytes
          
          Command Buffer 

          40 characters, exclusive of AT prefix, Carriage Return and spaces

          Control Commands    

          User-programmable nonvolatile memory (NRAM)
          Data compression
          Fixed/variable DTE and link rates

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                                                                COURIER HST


          Error control
          Error control result codes
          Transmit data flow control (hardware, software)
          Received data flow control (hardware, software)
          Command mode, online echoing
          Verbal/numeric result codes
          Standard, Extended, Advanced result code sets
          Result code display ON/OFF
          Speaker OFF, ON until CD, ON through CD and data transmission, ON
               after last digit dialed until CD
          Command Mode/online toggle
          Voice/data communications
          Adaptive dialing
          Fast dialing, search for dial tone
          Wait for second dial tone, then continue
          Wait for answer, then continue
          Dial alphabetic string
          Dial one of four phone numbers stored in NRAM
          Flash switch-hook to transfer call
          Reset to NRAM defaults
          Load ROM factory settings
          Request to Send (RTS) override
          Data Set Ready (DSR) override
          Break handling
          
          Test Options        

          Analog loopback (2400/1200/300 bps)
          Dial test
          Test pattern (2400/1200 bps)
          Analog loopback with test pattern (2400/1200 bps)
          
          Call Progress Codes

          NO DIAL TONE
          BUSY
          NO ANSWER
          RINGING
          VOICE
          
          Equalization        

          Adaptive









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                                                                COURIER HST


          Transmitter Carrier Frequencies    

          USR-HST
             Originate Mode:   350 Hz
                Answer Mode:   1800 Hz
          V.22bis, Bell 212A
             Originate Mode:   1200 Hz
                Answer Mode:   2400 Hz
          Bell 103
             Originate Mode:   
                       Mark:   1270 Hz
                      Space:   1070 Hz
                Answer Mode:
                       Mark:   2225 Hz
                      Space:   2025 Hz
          
          Receiver Carrier Frequencies

          USR-HST
             Originate Mode:   1800 Hz
                Answer Mode:    350 Hz
          V.22bis, Bell 212A
             Originate Mode:   2400 Hz
                Answer Mode:   1200 Hz
          Bell 103
             Originate Mode:   
                       Mark:   2225 Hz
                      Space:   2025 Hz
                Answer Mode:   
                       Mark:   1270 Hz
                      Space:   1070 Hz
          
          Certification  

          FCC Part 68 & Part 15, Subpart J, Class B Domestic; DOC (Canada)

          Power Adapter  

          UL listed, CSA approved, Supply voltage:  115 VAC, 60 Hz, 16 VAC
          Output

          Power Consumption

          10 watts

          Failed Call Timeout 

          30-sec. default, programmable 2-255 sec.




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                                                                COURIER HST


          Answer Tone Timeout 

          30 sec.

          Answer Tone Detector     

          2150-2300 Hz

          Loss of Carrier Timeout

          (Disconnect Timer) 0.7-sec. default, programmable 0.2-25.5 sec.

          Receive Sensitivity 

          -43 dBm

          Transmit Level 

          - 9 dBm

          Transmitter Frequency Tolerance

          .01 %

          Size

          8.30 x 12.65 x 1.57 inches

          























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