Fax Modem  (250-3581)   Fax Class 2 Operation Part 3   Faxback Doc. # 5885

Continued from Faxback Document # 5884

   TABLE 5-5 HANGUP STATUS CODES

CODE        CAUSE/DESCRIPTION

0-9         Call Placement and Termination
0           Normal and proper end of connection
1           Ring Detect without successful handshake
2           Call aborted, from +FK or AN
3           No Loop Current

10-19       Transmit Phase A & Miscellaneous Errors

10          Unspecified Phase A error
11          No Answer (T.30 T1 timeout)

20-39       Transmit Phase B Hangup Codes

20          Unspecified Transmit Phase B error
21          Remote cannot receive or send
22          COMREC error in transmit Phase B
23          COMREC invalid command received.
24          RSPEC error.
25          DCS sent three times without response.
26          DIX/DTC received 3 times; DCS not recognized
27          Failure to train at 2400 bps or +FMINSP value.
28          RSPREC invalid response received.

40-49       Transmit Phase C Hangup Codes

40          Unspecified Transmit Phase C error
43          DTE to DCE data underflow

50-69       Transmit Phase D Hangup Codes

50          Unspecified Transmit Phase D error.
51          RSPREC error
52          No response to MPS repeated 3 times.
53          Invalid response to MPS
54          No response to EOP repeated 3 times.
55          Invalid response to EOP
56          NO response to EOM repeated 3 times.
57          Invalid response to EOM.
58          Unable to continue after PIN or PIP.

70-89       Receive Phase B Hangup Codes

70          Unspecified Receive Phase B error.
71          RSPREC error.
72          COMREC error.
73          T.30 T2 timeout, expected page not received.
74          T.30 T1 timeout after EOM received.

90-99       Receive Phase C Hangup Codes

90          Unspecified Receive Phase C error.
91          Missing EOL after 5 seconds.
92          Unused code.
93          DCE to DTE buffer overflow.
94          Bad CRC or frame (ECM or BFT modes).

100-119     Receive Phase D Hangup Codes

100         Unspecified Receive Phase D errors.
101         RSPREC invalid response received.
102         COMREC invalid response received.
103         Unable to continue after PIN or PIP

120-255     Received Codes

5.4.1 +FCON, FACSIMILE CONNECTION RESPONSE

+FCON indicates connection with a fax machine.  It is released by
detection of HDLC flags in first received frame.  +FCON is generated in
response to an Originate or Answer command.

5.4.2 +FDCS:, REPORT CURRENT SESSION CAPABILITIES

Syntax:  +FDCS:VR, BR, WD, LN,DF, EC, BF, ST

+FDCS:<string> report the negotiated parameters.
Phase C data will be formatted as described by the subparameters.
This message may be generated in execution of +FDT or +FDR commands,
before the CONNECT result code, if new DCS frames are generated or
received.

5.4.3 +FDIS:, REPORT REMOTE STATION CAPABILITIES

Syntax: +FDIS:VR, BR, WD, LN,DG, EC, BF, ST
+FDIS:<string> report remote facsimile station
capabilities and intentions.  The parameters are provided in ASCII
notation.

This message is generated in execution of Origninate, Answer, +FDT, or
+FDR commands.

5.4.4 +FCFR, INDICATE CONFIRMATION TO RECEIVE

Syntax: +FCFR

The DCE sends a +FCFR response to the DTE upon reception of an acceptable
TCF training burst and an valid DCS signal from the remote machine.  This
indicates that the DCE will receive Phase C data after the remote station
receives the local DCE's CFR message.  The +FCFR message is generated in
execution of a +FDR command.

5.4.5 +FTSI:, REPORT THE TRANSMIT STATION ID

Syntax: +FTSI: "<TSI ID string>" Transmit Station 1

This response reports the received transmit station ID string, if any.
This message is generated in execution of Originate, Answer, +FDT, or
+FDR commands.

5.4.6 +FCSI:, REPORT THE CALLED STATION ID

Syntax: +FCSI: "<CSI ID string>" Call Station 1.

This response reports the received called station ID string if any.  This
message is generated in execution of Originate, Answer, +FDT, or +FDR
commands.

5.4.7 +FPTS:, RECEIVE PAGE TRANSFER STATUS

Syntax: +FPTS:<ppr>,<lc>
The +FPTS:<ppr> is generated by the DCE at the end of Phase C data
reception, in execution of a +FDR command.

The <ppr> is generated by the DCE; it depends on the DCE capabilities at
T.4 error checking.  See Table 5-4 for <ppr> values.

The receiving DCE will count the lines and report the count as a decimal
number in the <lc> parameter.

A receiving DTE may inspect <ppr> and write a modified value into the
+FPTS parameter.  The DCE will hold the corresponding Post Page Response
message until released by a +FDR command from the DTE.

5.4.8 +FET:, POST PAGE MESSAGE RESPONSE

Syntax: +FET<ppm>

The +FET<post page message> response is generated by a receiving DCE after
the end of Phase C reception, on receipt of the post-page message from
the transmitting station.

The +FET:<ppm> response is generated in execution of a +FDR command.  The
<ppm> codes respond to the T.30 post page message (Table 5-3).

5.4.9 +FPTS:, TRANSMIT PAGE TRANSFER STATUS

Syntax: +FPTS :<ppr>

The +FPTS: response reports a <ppr> number representing the coy quality
and related post-page message responses received from the remote DCE.  The
set of valid <ppr> values are defined in Table 5-4.

The +FPTS:<ppr> response is generated in execution of a +FET=<ppm>
command.

5.4.10 +FHNG: CALL TERMINATION WITH STATUS

Syntax: +FHNG:<hangup status code>

+FHNG indicates that the call has been terminated.  The hang-up cause is
reported, and stored in the +FAXERR parameter for later inspection.  The
<hangup status code> values are described in Table 5-5.

+FHNG:<hsc> is a possible intermediate result code to any DTE action
command described in Section 5.3.  It is always followed by the OK final
result code.

Upon termination of a call, the DCE determines the cause of termination,
and reports it as part of the FHNG:<hsc> response.  It also stores this
<hsc> code in the +FAXERR parameter for later inspection.

The hang-up values are organized according to the phases of the facsimile
transaction as defined by T.30.  In the Figure A/T.30 flow charts, there
are decision boxes labelled "Command Received?"; this is referred to as
COMREC in the table.  Similarly, decision boxes labelled "Response
Received?" are referred to as RSPREC in the table.  A COMREC error or
RSPREC error indicates that one of two events occurred :1) a DCN
(disconnect signal was received, or 2) an FCS error was detected and the
incoming signal was still present after 3 seconds.  (See Figure A/T.30).

The table values are in decimal notation.  Leading zero characters are
optional.

5.5 SERVICE CLASS 2 PARAMETERS

All service Class 2 parameters can be read, written and tested fro range
of legal values by the DCE.  The general syntax is described in Section
5.1.

Group 3 FAX devices negotiate session parameters in DIS, DCS, and DTC
frames.  The following parameters are provided to condition the facsimile
DCE for the capabilities it will offer, and to report the session settings
negotiated.

The three primary T.30 session parameters are +FDCC, +FDIS and +FDCS.

5.5.1 +FDCC,DCE CAPABILITIES PARAMETERS

Write Syntax: +FDCC= VR, BR, WD, LN, DF, ED, BF, ST

Valid values see Table 5-2.

Default values 0, 3, 0, 2, 0, 0, 0.0

+FDCC allows the DTE to sense and constrain the CAPABILITIES of the
facsimile DCE, from the choices defined in CCITT T.30 Table 2.  When
+FDCC is modified by the DTE, the DCE copies +FDCC into +FDIS.

5.5.2 +FDIS, CURRENT SESSION CAPABILITIES PARAMETERS

Write Syntax: +FDIS= VR, BR, WD, LN, DF, EC, BF, ST

Default Values:  0, 3, 0, 2, 0, 0, 0, 0
Valid values See Table 5-2.

The +FDIS parameter allows the DTE to sense and constrain the capabilities
uses for the current session.  The DCE used +FDIS to generate DIS or DTC
messages directly, and uses +FDIS and received DIS messages to generate
DCS message.

The DCE initializes the +FDIS parameter from the +FDCC parameter on
initialization, when +FDCC is written, and at the end of a session.

5.5.3 +FDCS, CURRENT SESSION RESULTS PARAMETERS

Read Syntax: +FDCS?

DCE response:+FDCS = VR, BR, WD, LN, DF, EC, BF, ST OR +FDCS=

Valid values See Table 5-2.

Default Values 0, 0, 0, 0, 0, 0, 0, 0.

The +FDCS parameter is loaded with the negotiated T.30 parameters for the
current session.  A transmitting DCE generates DCS; a receiving DCe gets
DCS from the remote station.  The DTE may read this parameter.

The +FDCS parameter is initialized 0, 0, 0, 0, 0, 0, 0, 0. on
initialization, and at the beginning of a session.  If the DTE issues
a +FDCS? command in the initial state, the DCE reports.

<CR><LF>0.0, 0.0, 0.0. <CR><LF>

The contents of +FDCS are spontaneously reported during execution of +FDR
or +FDT commands, by the +FDCS: VR, BF, WD, LN, BF, EC, BP, ST response,
using the same compound parameter format.  Several commands and responses
reference T.30 session negotiated parameters.  These are described by a
set of command subparameters.  These subparameters are described in Table
5-2 with note.  Optional parameter value are marked with an "*".
Unspecified parameter values are reserved for future use.

The +FDCC, +FDIS and +FDCS compound parameters use these session
parameters.  On writes, unspecified subparameters are unchanged.

The +FDIS:, +FDCS: and +FDTC: session report responses use these
subparameters.

For test response, ranges of values are reported for each subparameter
enclosed in parentheses characters.  For example, a DCE response to
+FDCC =? could report:

<CRLF> (0,1), (0-3), (0-2), ((0-2), (0-2), (0), (0-7)
<CRLF>
Use Example:
+FDIS= 0, 3, 0, 2, 0, 0, 0, 1 =

VR=0   98 dpi Vertical Resolution

BR=3   9600 Bit/s

WD=0   1728 pixels

LN=2   Unlimited Length

DF=0   1-D Modified Huffman coding.

EC=0   No ECM.

BF=0   No BFT.

ST=1   5 ms scan time.

Continued on Faxback Document # 5886

(SMC-04/07/94)