PCCA at Command Set Annex D

PCCA
STANDARD
Data Transmission Systems and Equipment - Serial Asynchronous Automatic Dialing and Control for Character Mode DCE on Wireless Data Services -
Annex D: PAD Control
PCCA ANX-101-D
OFFICIAL STANDARD, Version 1.0, 21 JANUARY, 1997
PORTABLE COMPUTER AND COMMUNICATIONS ASSOCIATION

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January, 1997

Portable Computer and Communications Association
Modem Standards Committee
P.O. Box 917
Brookdale, California 95007 U.S.A
Telephone: (408) 338-7701
Fax: (408) 338-7806

PCCA ANX-101-DIssue OJanuary, 1997

1. Scope2

2. Normative References2

3. Compliance3

4. PAD Control Commands4

4.1. PAD Control Parameter Commands4

4.1.1. Time-Independent Escape Sequence Enable4

4.1.2. Disconnect Procedure5

4.1.3. Local Online Echo Enable6

4.1.4. Forwarding Character Feature Mask7

4.1.5. PAD Primary Forwarding Character8

4.1.6. PAD Secondary Forwarding Character8

4.1.7. Packet Termination Upon Entering Online Command State9

4.1.8. No Data Disconnect9

4.1.9. Data Disconnect10

4.1.10. PAD Break Handling10

4.1.11. PAD Inter-Character Timer11

4.1.12. PAD Inter-Line Timer11

4.1.13. PAD Input Buffer Editing Enable12

4.1.14. PAD Input Buffer Backspace Character13

4.1.15. PAD Maximum Packet Length13

4.2. PAD Control Action Commands14

4.2.1. Display Memory Usage14

4.2.2. Flush WAN-bound Data Buffer14

4.2.3. Display Supported Annex D Commands15

5. Additions to +W Command16

PCCA ANX-101-DIssue OJanuary, 1997

1. Scope

This standard defines optional extensions to the protocol elements, procedures, and behaviors defined in PCCA STD-101. These extensions are based on the +WS and +WC command prefixes reserved by PCCA STD-101 for standardized extensions. The reader is presumed to be familiar with the text of PCCA-STD-101.

This standard constitutes an annex to PCCA STD-101 (designated Annex D) specifying optional commands common to most wireless modems, in accordance with the annex schedule set forth in PCCA STD-101 Section 8.4, Reserved Topics. The commands defined in this annex permit additional control of a packet assembler / dissassembler in wireless-capable Data Communications Equipment (DCE), for communication with a wide-area network (WAN).

The commands defined in this standard extend the Common AT Command Set and have both unrestricted visibility and global scope, in accordance with PCCA XSTD-101 Section 5.4.1:

All DCE parameters controlled by AT commands in the Common AT Command Set (ref. Figure 5) must have unrestricted visibility and global scope, unless other visibility or scope is defined explicitly in an applicable standard. Some of these parameters may have unstable or stable volatility. All AT commands defined in this standard are, by definition, in the Common AT Command Set. Annexes of this standard may define optional additions to the Common AT Command Set.

In the case of parameter commands defined in this Annex, a single value of the parameter is shared by all implemented Wireless (or Wireline) Data Service (WDS) types, and the Data Terminal Equipment (DTE) must reprogram the parameter value as necessary when changing WDS types via the +WS46 command; the parameter command must be available for every supported value of +WS46. In the case of action commands defined by this Annex, the action command must be available for every supported value of +WS46 and always acts upon the currently selected WDS type.

The parameters in this Annex only affect operation of the DCE in Transparent Character Stream mode and in Reliable Transparent Character Stream mode (as selected by +WS45=0 or by +WS45=1).

2. Normative References

The following standards and other publications contain provisions or normative references which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Each publishing standards body maintains a register of currently valid national, international, and industry standards published by them.

PCCA STD-101Data Transmission Systems and Equipment - Serial Asynchronous Automatic Dialing and Control for Character Mode DCE on Wireless Data Services, PCCA Recommended Standard, July, 1995

3. Compliance

For compliance with this Annex, a DCE must implement all commands described herein. A DCE, however, may still be compliant with PCCA STD-101, and implement a partial set of the commands in this Annex. The following is a suggested guideline for implementations which are not fully compliant with this Annex.

This Annex defines several commands which should be implemented in sets. If either +WS72 or +WS73 is implemented, then both should be implemented. If +WS63 is implemented, then either +WS64 or +WS65 should be implemented.

4. PAD Control Commands

4.1. PAD Control Parameter Commands

This section describes PAD Control Commands that conform to TIA-615 rules for parameter commands.

4.1.1. Time-Independent Escape Sequence Enable

Syntax:+WS60=n
+WS60
+WS60=?

Description:Enables the Time-Independent Escape Sequence (TIES) as an additional mechanism for return to the online data state (other than any mechanism enabled by the &D command). Defined values are:
0TIES disabled.
1TIES enabled.

Implementation:+WS60=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.2. Disconnect Procedure

Syntax:+WS61=n
+WS61?
+WS61=?

Description:Determines the procedure used by the DCE in disconnecting (transitioning from the online state to the offline command state). Defined values are:
0 - Terminate packet, transmit buffered WAN-bound data packets before disconnect.
1 - Do not terminate packet currently being constructed, but do transmit any buffered WAN-bound data packets before disconnect.
2 - Flush data and disconnect.
3 - Flush data, deregister, and disconnect (same as 2 if the selected WAN does not support deregistration).

Implementation:Note that the disconnect procedure as determined by +WS61 may not be followed in its entirety if the DCE is out of communication with the WAN.
+WS61=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.3. Local Online Echo Enable

Syntax:+WS62=n
+WS62?
+WS62=?

Description:Enables or disables the DCE’s capability to echo data from the DTE in the online state. Defined values are:
0Local Online Echo disabled
1Local Online Echo enabled

Implementation:If Local Online Echo is enabled, the DCE will echo each character received from the DTE during the online state. If both Local Editing and Local Online Echo are enabled, upon receipt of the backspace character (determined by +WS73), the DCE will echo the following character sequence to the DTE:
backspace character
space (2016)
backspace character
+WS62=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.4. Forwarding Character Feature Mask

Syntax:+WS63=n
+WS63?
+WS63=?

Description:This register contains a bit mask that controls the PAD’s use of the primary and secondary forwarding characters. The bit assignments are as follows:
Bit 0 - If set, the PAD will terminate WAN-bound packets upon receipt of the primary forwarding character from the DTE.
Bit 1 - If set, the PAD will include the primary forwarding character in WAN-bound data (i.e., will not filter-out the primary forwarding character).
Bit 2 - If set, the PAD will terminate WAN-bound packets upon receipt of the secondary forwarding character from the DTE.
Bit 3 - If set, the PAD will include the secondary forwarding character in WAN-bound data (i.e., will not filter-out the secondary forwarding character).
Bit 4 - Unused
Bit 5 - Unused
Bit 6 - Unused
Bit 7 - Unused

Implementation:If either +WS64 or +WS65 are implemented, +WS63 must be implemented. If +WS65 is not implemented, the DCE will ignore bits 2 and 3 of +WS63. If +WS64 is not implemented, the DCE will ignore bits 0 and 1 of +WS63
+WS63=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:3 (bits 0 and 1 set) - if +WS64 is implemented
15 (bits 0, 1, 2, and 3 set) if both +WS64 and +WS65 are implemented.
12 (bits 2 and 3 set) if only +WS65 is implemented.

4.1.5. PAD Primary Forwarding Character

Syntax:+WS64=n
+WS64
+WS64=?

Description:Receipt of this character (if enabled in the Forwarding Character Feature Mask) will cause the DCE to terminate the packet, and to begin transmission of the packet to the WAN. Defined values are:
0-255

Implementation:If +WS64 is implemented, +WS63 must be implemented.
+WS64=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:13

4.1.6. PAD Secondary Forwarding Character

Syntax:+WS65=n
+WS65
+WS65=?

Implementation:If +WS65 is implemented, +WS63 must be implemented.
+WS65=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:13

4.1.7. Packet Termination Upon Entering Online Command State

Syntax:+WS66=n
+WS66?
+WS66=?

Description:Determines whether or not the PAD will terminate an unterminated WAN-bound packet if the DCE enters the Online Command State. Defined values are:
0Packet will not be terminated.
1Packet will be terminated.
If 0 is chosen, all buffered characters in the unterminated WAN-bound packet will be discarded when the DCE enters the Online Command State.

Implementation:The disconnect procedure determined by +WS61 may override the behavior determined by +WS66.
+WS66=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:1

4.1.8. No Data Disconnect

Syntax:+WS67=n
+WS67?
+WS67=?

Description:Number of minutes of continuous loss of WAN contact, after which the DCE transitions to the offline command state if there is no buffered WAN-bound data. Defined values are:
0“No Data Disconnect” disabled.
1 - 255Delay in minutes for “No Data Disconnect”.

Implementation:If the DCE is unable to communicate with the WAN, it may be impossible for the DCE to perform all of the actions defined by +WS61 when performing a “No Data Disconnect”.
+WS67=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.9. Data Disconnect

Syntax:+WS68=n
+WS68?
+WS68=?

Description:Number of minutes of continuous loss of WAN contact, after which the DCE transitions to the offline command state even if there is buffered WAN-bound data. Defined values are:
0“Data Disconnect” disabled.
1 - 255Delay in minutes for “Data Disconnect”.

Implementation:If the DCE is unable to communicate with the WAN, it may be impossible for the DCE to perform all of the actions defined by +WS61 when performing a “Data Disconnect”. Specifically, all WAN-bound data will be flushed when performing a “Data Disconnect”.
+WS68=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.10. PAD Break Handling

Syntax:+WS69=n
+WS69?
+WS96=?

Description:Determines the action to be taken by the DCE upon receipt of a break from the DTE (while in the Online state). Defined values are:
0 - Take no action
1 - Return to the Online Command state
2 - Disconnect, and return to the offline command state

Implementation:If +WS69 is set to 2, the DCE will follow the behavior determined by +WS61 (Disconnect Procedure).
+WS69=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.11. PAD Inter-Character Timer

Syntax:+WS70=n
+WS70?
+WS70=?

Description:Delay time after which the DCE will terminate a packet (and forward it to the WAN) if no input is received from the DTE and no other packet termination conditions have been met. Supported values are:
0Inter-Character Timer disabled
1 - 255Delay in tenths of seconds.

Implementation:If no characters are received from the DTE in the time specified, the DCE will terminate the packet and forward it to the WAN.
+WS70=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:50

4.1.12. PAD Inter-Line Timer

Syntax:+WS71=n
+WS71?
+WS71=?

Description:Delay time after which the DCE will terminate a packet (and forward it to the WAN) if a carriage return is not received from the DTE, and no other packet termination conditions have been met. Supported values are:
0Inter-Character Timer disabled
1 - 255Delay in tenths of seconds.

Implementation:If a carriage return is not received from the DTE in the time specified, the DCE will terminate the packet and forward it to the WAN.
+WS70=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.13. PAD Input Buffer Editing Enable

Syntax:+WS72=n
+WS72?
+WS72=?

Description:Enables or disables the DCE’s capability to perform local editing of WAN-bound data. Values are:
0Local editing disabled.
1Local editing enabled

Implementation:If local editing is enabled, the DCE will remove one character from the PAD’s input buffer upon receipt of the character specified by +WS73. If both local editing and local echo are enabled, upon receipt of the backspace character, the DCE will echo the following character sequence to the DTE:
backspace character
space (2016)
backspace character
If the PAD’s input buffer is empty (or contains only backspace characters), when a backspace character is received, the character will be appended to the contents of the input buffer, regardless of whether or not local editing is enabled. (i.e., the PAD will not drop the backspace under these conditions even if local editing is enabled.)
If +WS72 is implemented, +WS73 must be implemented.
+WS72=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the supported values.

Recommended Default:0

4.1.14. PAD Input Buffer Backspace Character

Syntax:+WS73=n
+WS73?
+WS73=?

Description:Selects the character to be used by the DCE as “backspace” if local editing is enabled (via +WS72).

Recommended Default:8

4.1.15. PAD Maximum Packet Length

Syntax:+WS74=n
+WS74?
+WS74=?

Description:Sets the maximum length of packet to be generated by the DCE. Upon receipt of +WS74 characters from the DTE, the DCE will terminate the packet, even if other packet termination conditions have not yet been met.

Implementation:The range of values is manufacturer-specific, with the exception that 0 is not an allowable value.
+WS74=? behaves according to TIA-615 rules for parameter commands, and must enumerate only the valid range of values.

Recommended Default:255

4.2. PAD Control Action Commands

This section describes PAD Control Commands that conform to TIA-615 rules for action commands.

4.2.1. Display Memory Usage

Syntax:+WCMEM
+WCMEM=?

Description:Displays the usage of memory by the DCE’s PAD.
The command displays free-form information text (not a string constant) which must conform to TIA-615 and PCCA XSTD-101 format rules. The information text will consist of at least four lines, containing the following information: 1) the number of bytes of DCE memory available for buffering DTE-bound data, 2) the number of bytes of DCE memory available for buffering WAN-bound data, 3) the amount of DTE-bound data buffered by the DCE, and 4) the amount of WAN-bound data buffered by the DCE. Items 3 and 4 may be specified in bytes, packets, or other units selected by the manufacturer.

Implementation:The form of all information text output by the +WCMEM command is manufacturer-specific.
+WCMEM=? behaves according to TIA-615 rules for action commands having no subparameters.

4.2.2. Flush WAN-bound Data Buffer

Syntax:+WCFLSH
+WCFLSH=?

Description:Flushes all WAN-bound data from the DCE.

Implementation:Behavior with respect to any partially-transmitted packets is manufacturer-specific.
+WCFLSH=? behaves according to TIA-615 rules for action commands having no subparameters.

4.2.3. Display Supported Annex D Commands

Syntax:+WCXD
+WCXD=?

Description:This command allows the DCE to report back to the DTE which of the commands defined in this Annex it has implemented.
When the DTE invokes this action (via +WCXD) the DCE must output the names of implemented PAD Control Commands. Each name will be delimited by double quotes, the quoted strings being separated by commas. The list includes the names of all supported Annex D commands, with the exception of +WCXD which is not reported. The output may occupy multiple lines, following TIA-615 rules for information text.
For example, a DCE operating in verbose mode and supporting only the +WS60 and +WS61 commands (besides +WCXD) would respond to +WCXD with:
“+WS60”,”+WS61”<end-of-info-text delimiter, e.g. CR/LF>
OK<delimiter>