gtps1m26System Macros

CTKL-SLC Channel Keypoints Setup

Use this system macro to generate the link keypoint (LK4KC) and channel keypoints (LK5LC) that are required to operate and control TPF synchronous links. These keypoints are stored on file as program records and assembled by using one or more CTKL statements.

Format

If you want to generate a link keypoint, use the following format. The parameters required in each case are listed separately.















Each program record (segment) comprises one link keypoint and hence only one CTKL macro is required within the envelope of BEGIN/FINIS statements.

TYPE=LK4
Causes expansion of a link keypoint.

P1024=YES|NO
Defines whether the link operates according to the SITA link control procedure P1024 or the ATA/IATA synchronous link control contained in ATA/IATA interline communications manual DOC/GEN 1840, Chapter V.

CHANS=literal1
Defines the number of full duplex pairs (AI lines) comprising the link. Its value can range from 1 to 7.

RELSLN=literal2
All lines attached to the TPF system are allocated sequential symbolic line numbers defined in SYCON. Literal 2 defines the lowest numbered AI line assigned to this link relative to the minimum symbolic line number assigned to AI lines in SYCON. The lowest RELSLN value is 0 (zero).

NEXT=symbol1

LAST=YES
These parameters are mutually exclusive and either provide, through symbol1, the name of the next program record (segment) in the chain of keypoints or else indicate, through LAST=YES, that this program record is the last one in the chain.

MAXBLK=literal3
Defines the maximum number of characters in data message blocks exchanged on the link from DLE to ETB inclusive. It does not include BCC. The default value is 255.

T1=literal4
Defines the NAK/ENQ/Data Procedure timeout and repetition frequency. The default value is 3 seconds.

T2=literal5
Defines the idle line timeout and repetition frequency. The default value is 3 seconds.

P=literal6
Defines the frequency of acknowledging data message blocks (notwithstanding the fact that all blocks of multiblock messages will be acknowledged individually). The default value is 1.

N2=literal7
Defines the number of consecutive idle line or ENQ timeouts that cause the line to be out of service (LOS). The default value is 3.

HEN=literal8
If the link is connected at its other end to a high level network (for example SITA HLN) literal8 must be four hexadecimal characters defining the address of entry centre (HEN) to that network. This parameter must be included if P1024 = YES, otherwise a default value of zero is assumed.

TSIEXH=literal9
Defines the number of outstanding TSIs not acknowledged that causes the TPF system to inhibit data message block transmission and enter the enquiry procedure (TSI Exhaustion). The default value is 5.

AML=YES|NO
Defines whether AML link control blocks are exchanged when all blocks of a multiblock message have been correctly received and acknowledged to clear that message label for reuse by the transmitting center.

If the parameter is omitted, the value assigned depends on the parameter P1024:

If P1024=YES and AML=NO is coded, the parameter is accepted and a warning message generated.

SPREAD=YES|NO
Defines whether blocks of multiblock messages can be transmitted on different channels of a multichannel link (also called scatter).

If the parameter is omitted, the value assigned depends on the parameter P1024:

If P1024=YES and SPREAD=YES is coded, the parameter is accepted and a warning message generated.

ILB=YES|NO
Defines whether ILB link control blocks are exchanged in idle line conditions. The default value is ILB=NO

If P1024=YES and ILB=YES is coded the parameter is accepted and a warning message generated.

ENQREP=ACK|RSM
Defines whether the response to ENQ and ILB link control blocks are ACK in addition to RSM or STP or are restricted to RSM or STP. The default value is ENQREP = ACK.

EXSYN=*|4|8|12
Defines the number of extra SYN characters at the start of a data transmission additional to the number generated automatically by the hardware. The default value is 0 (zero).

MBIXDLY=literal10
Defines the time delay after discovering MBI exhaustion for A-type messages before attempting further processing by the output message handler. The default value is 6.

MAXBQ=literal11
Defines the maximum number of message blocks on the link B-type output message queue which inhibits the output message handler from adding further original message blocks. The default value is 3.

RSTBQ=literal12
Defines the minimum number of message blocks on the link B-type output message queue which allows the CCP to control transfer to the output message handler. The default value is 2.

HDR=YES|NO
Defines whether all A-type traffic on this link, with the exception of traffic that originated from a pseudo high-speed line, contains routing information in a standard message header, or not.

If this parameter is omitted, it is assumed that the message will not contain routing information.

ORIGID=literal13
This parameter defines the symbolic origin application name assigned to nonPLN, A-type traffic on a link that does not support the message routing header. Literal 13 must be four decimal characters. A default of 0000 is generated if this parameter is required, but not included.

DESTID=literal14
This parameter defines the symbolic destination application name assigned to nonPLN, A-type traffic on a link that does not support the TPF message routing header. Literal 14 must be four decimal characters. A default of 0000 is generated if this parameter is required, but not included.

ACI=OMIT|INCLUDE
Defines whether the optional additional characteristics indicator (ACI) byte is to be included in the control character envelope which accompanies each information block. If the parameter is omitted, the value assigned is dependent upon the P1024 specification:

When actually coding the ACI parameter, the validity of the definition is dependent upon the P1024 parameter. Therefore, P1024=NO, ACI=OMIT, P1024=NO, ACI=INCLUDE, and P1024=YES, ACI=INCLUDE are valid combinations while P1024=YES, ACI=OMIT are not valid combinations.

LINCODE=CCITT#5|CCITT#2|EXITT#5|ALC
Defines the code translation to be performed on message block text when the optional ACI character is not a component of the control character envelope (ACI=OMIT). If the parameter is omitted, the value generated is LINCODE=CCITT#5. The text translation specifications follow here.

 CCITT#5 
CCITT No. 5 code (ASCII/ISO 7 bit code)

 CCITT#2 
Padded CCITT No. 2 code (Padded Baudot)

 EXITT#5 
Extended CCITT No. 5 code

 ALC 
Padded 6 bit code (Padded ALC).

Only one translation code can be specified for each link when using this parameter.

T6=literal15
Defines the time interval allowed between receipt of the last ACK of a multiblock message and the acknowledge message label (AML) LCB before the entire message will be retransmitted. T6 is an alternate value to T1 and overrides the latter when defined. The T6 parameter is invalid for P1024 = YES.

When the alternate AML timer, T6, is defined, the value must be between 1 and 63 inclusive. When T6 is not to be defined, omit the parameter.

T7=literal16
Defines the time interval allowed between receipt of successive blocks of a multiblock message before the partially received message is discarded. This parameter is invalid for P1024 = YES.

When a message discard timer value, T7, is used, the value must be between 1 and 63 inclusive. When T7 is not used, omit the parameter. This implies that partially received messages will not undergo a "time out" and be discarded.

N3=literal17
Defines the number of times a multiblock message is retransmitted in its entirety when no Acknowledge Message Label (AML) LCB has been received. This parameter is invalid for P1024 = YES.

When message retransmission is to occur, N3 must be a value specified between 1 and 12 inclusive. When no message retransmission is to occur, the N3 parameter must be omitted.

S1=literal18
No ACK received timer. After a message block has been sent, an ENQ is generated by the link control handler if an ACK is not received within S1 seconds. The S1 timer is reset after an LCB with parity errors is received and after a message block has been sent. Default value is 3.

S7=literal19
No block received timer. When no data or control block has been received for more than S7 seconds, the link control handler generates an ENQ. The S7 timer is reset upon receipt of a control or data block and after an ENQ has been generated. Default value is 4.

S8=literal20
Channel down timer. When a channel is declared to be down, the link control handler starts the channel down timer (S8). This timer is reset should the link control handler declares the link down. While the S8 timer is running, the link control handler does not generate or accept data or control blocks. When the timer expires an ENQ is generated. Default value is 15.

S10=literal21
Multiblock message timer. If, during reception of a multiblock message S10 seconds have elapsed during which another block of that message has not been received, the link control handler gives to the supervisor those blocks so far received and clears the message label. Default value is 60.

Z5=literal22
STP N/M repetitions. If, after a channel has been declared down, other channels of the link remain operative, the link control handler sends Z5 SXTs at intervals of T1 seconds. Default value is 3.

LOOPTST=YES|NO
To describe whether or not a loop test configuration between two centers will be established. Default is no.

LOOPBIT=ONE|ZERO
Subject to bilateral agreement between centers, bit 6 of the TSI in link control blocks can be used to indicate the center originating the control block. It is set to 1 at one end of the link and to 0 (zero) at the other.

RETRANS=YES|NO
Indicator as to whether or not to retransmit complete message on channel down condition. Default is no.

If you want to generate a channel keypoint, use the following format.



Each program record (segment) makes up one channel keypoint. Hence, only one CTKL macro is required between BEGIN and FINIS statement.

TYPE=LK5
Causes expansion of one channel keypoint

CHANS=1
Defines one channel keypoint to be generated by this CTKL statement.

RELSLN=literal14
Literal14 defines the lowest numbered AI line whose keypoint is being generated by this CTKL statement relative to the minimum symbolic line number assigned to AI lines in SYCON. The lowest RELSLN value is 0 (zero).

RELKCN=literal15
Literal15 defines the lowest numbered AI line whose keypoint is being generated by this CTKL statement relative to the first AI line comprising the link. The lowest RELKCN value (for the first channel assigned to this link) is 0 (zero).

NEXT=symbol1

LAST=YES
See the previous section for information about the RELKCN parameter and generating a LINK keypoint.
Note:
When more than one CTKL statement is necessary in one program assembly, each requires this parameter.

P=literal 6
See the previous section for information about the P parameter and generating a LINK keypoint.
Note:
When more than one CTKL statement is necessary in one program assembly, each requires this parameter.

TSIEXH=literal9
See the previous section for information about the TSIEXH parameter and generating a LINK keypoint.
Note:
Where more than one CTKL statement is necessary in one program assembly, each requires this parameter.

Entry Requirements

SYGLB, SYSET, SYCON, and CAIEQ must be called before issuing the CTKL macro.

Return Conditions

This is not an executable macro, therefore return conditions are not applicable.

Programming Considerations

Examples

None.