7_3_03.txt

传真编程的一些文档

      |
      |
























                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
                                                                               |
























                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                                                                 |
























                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |
                                                                                                                  |


























                                                         Table [T5.30], p.



                                                         FIGURE 5/T.30, p.





       3.2         Phases B, C and D - Facsimile procedure


            When entering phase B, the following rules should  be  adhered
       to:

            All manual receivers and all auto-answering units  must  enter
       phase  B by identifying their capabilities (i.e. Node R of the flow
       diagram  in  S 4.2  or 5.2).  All  manual  transmitters   and   all
       auto-calling  units must enter phase B prepared to detect the capa-
       bilities  and  issue   the   appropriate   mode   setting   command
       (i.e. Node T  of the flow diagram in S 5.2). To allow for operating
       method 2-R, the delay between the transmission of the digital iden-
       tification  signals  shall  be  4.5 seconds _ | 5% when sent from a
       manual facsimile receiver.

            The detailed information pertaining to the  tonal  and  binary
       coded  facsimile  procedures  is contained in SS 4 and 5 below. The
       relationship between these two procedures and an overview regarding









       the total system operation is given in the following:


       3.2.1         The interaction between tonal and binary  coded  pro-
       cedures


            Facsimile procedures, as described in this Recommendation, may
       be realized in two different ways:

               -          tonally, with a limited number of tones for sim-
       ple procedures (see S  4 below) and

               -         binary coded, for more  comprehensive  procedures
       (see S 5 below).

            Binary coded signalling is especially desirable  for  machines
       which use:

               -         comprehensive automatic functions;

               -          digital  concepts  internally  (e.g.  redundancy
       reduction techniques);

               -         fast transmission rates (in order  to  keep  pre-
       and post-message time short compared to total transmission time);

               -         special security features.

            Recommendations concerning the interaction between  tonal  and
       binary  coded signalling recognize the principle of the priority of
       coded procedures such that, when available, binary coded signalling
       shall be tried first. The interaction steps are as follows:

               -         The unattended called station shall answer a call
       with the CED signal.

               -         The unattended calling station shall  indicate  a
       call with the CNG signal.

               -          Whenever it is capable of binary  coded  signal-
       ling, the called station will start with binary coded signalling.

               -         Facsimile stations being capable of tonal signal-
       ling only will start tonally.

               -         Facsimile stations being capable of  both  binary
       coded  and  tonal  signalling  will send a sequence of signals, the
       first being a binary coded signal and the second and all  following
       signals being a composite of tonal and binary coded information.

               -         If the calling station reacts binary  coded  then
       the binary coded signalling goes on through all control procedures.

               -         If the calling station reacts tonally,  then  the
       tonal signalling goes on through all procedures.










            An example of a station having  both  binary-coded  and  tonal
       capabilities is shown in Figure 6/T.30 for further clarification.


       3.2.2         Signal sequences


            The recommended system utilizes  the  interchange  of  signals
       between  the  two  equipments  to  verify  compatibility and assure
       operation. To do this,

            the called station identifies its capabilities tonally (in the
       simplest  configuration)  and/or  binary coded. The calling station
       responds to this accordingly  with  a  command  tonally  or  binary
       coded. Now the transmitter continues phase B.

            Following the transmission of  the  message,  the  transmitter
       sends an end-of-message signal and the receiver confirms reception.
       Multiple documents can then be transmitted  by  the  repetition  of
       this procedure.

            The flow of signals is shown in Figure 7/T.30 for  the  confi-
       guration  where  the calling station is transmitting. These signals
       may be  tonal  or  binary  coded,  subject  to  the  conditions  of
       S 3.2.1 above.



                                                         Figure 6/T.30, p.





                                                         Figure 7/T.30, p.


            The condition where the calling station is  to  receive  docu-
       ments  is  shown  in Figure 8/T.30. The simple tonal systems do not
       provide this capability.


                                                         FIGURE 8/T.30, p.





       3.3         Phase E - Call release


            Call release occurs after the last post-message signal of  the
       procedure or under certain conditions, e.g.:


       3.3.1         Time out










            When a signal as specified by the facsimile procedure  is  not
       received  within  the  specified time-out period, the apparatus may
       signal to the operator (if one is in attendance) or disconnect  the
       telephone  connection.  The appropriate time-out periods are speci-
       fied in SS 4 and 5 below.


       3.3.2         Procedural interrupt


            The facsimile procedure may be interrupted by sending  a  pro-
       cedural interrupt signal, by notifying the attending operator or by
       disconnecting the connection. The signal is  defined  in  SS 4  and
       5 below.


       3.3.3         Command


            In the case where binary coded procedures  are  utilized,  the
       call  may be immediately terminated by the binary coded system com-
       mands, as specified in S 5 below.


       4       Tonal signalling for facsimile procedure


            This signalling system covers  operating  methods 1-T  and 2-T
       and  has  to  be  implemented  for apparatus operating according to
       Recommendations  T.2 and T.3.


       4.1         Description


       Phases B and C


                                  H.T. [T6.30]

                 _______________________________________________
                          Transmitter              Receiver
                 ___