gtpn1m0wNon-SNA Data Communications Reference

File Resident CCP

File resident communications control program segments perform the following functions:

Restart Initialization

Activated by the restart scheduler CTKS to initialize the poll status table with pointers to the channel keypoints and set pointers to the link keypoints in the CCWA for each line of the link.

Restart/Line Validation

This program may be activated in three ways:

Start Lines/Links

Activated by the following command entries:

Its purpose is to start a single line, all lines of a link, or all lines. It sets the line as started in the line status table and activates the link controller through CREMC informing it which lines are to be started.

In addition, this routine is also activated internally from either the cycle schedule in response to a ZCYCL command to restart any AI lines that had previously been started, or from 03-LRFIG to facilitate the assignment or replacement of individual AI lines, or communications control units that include AI lines.

Stop Lines/Links/Cycle Down Links

Activated by the command entries:

Its purpose is to stop a single line, all lines of a link or all lines. It is also entered by the cycle schedules on system cycle down. This program enters the link controller to stop activity on the appropriate channels. On return, when I/O activity has ceased, it updates the line status table and releases any core blocks attached to the CCWAs.

This routine is also activated internally by 03-LRFIG to facilitate the idling or assignment of individual AI lines, or communications control units that include AI lines.

Display Link Status

Link and line status is stored in the link and channel keypoint records and line status is also contained in the line status table.

The command entries:

cause selected status indicator bytes to be displayed for a single line, all lines of a link or all lines.

Invalidate Line

This program is entered to turn down a line on which an uncorrectable I/O error has occurred. It will enter the link controller to stop the affected line. On return, it will set the line as stopped in the line status table and will housekeep all associated table entries and controls, so that on restart they are in an initial condition.

This routine is also activated internally by 03-LRFIG to facilitate the idling or assignment of individual AI lines, or communications control units that include AI lines.

Line And Link Error Counts

Line and link error counts are accumulated and stored in file resident records.

Initialize Error Counts

This program is entered by the command entry:

to initialize the file resident records setting all error counts to zero.

Update Error Counts

This program is entered at regular intervals by the communications timer program to update the file resident records with the line error counts from the CCW areas and the link error counts from the channel keypoint records.

Display Line and Link Error Counts

This program is entered by the command entries:

to display the line and link counts for a single line, all lines of a link or all lines.

Display Or Alter Restart/Shutdown Level

The CCP has the ability to inhibit the receipt of data message blocks on all links based on the size of the input list. This program is entered by the commands:

to display or alter the control levels.

Alarm/Message Generator

This program handles the generation and transmission of alarm and error messages and is activated as a result of the Link Alarm macro, KARMA or by direct enter (ENTNC/ENTRC).

Start/Stop And Display Pseudo Lines

This program is entered by the command entries:

to start, stop or display the polling status of the high speed lines controlled by satellite processors attached to a SITA high level network exit center. It is also activated when a link is restarted to restore the polling status automatically.

SLC SITA P1024 Test Driver and Monitor

These programs are designed to perform those test functions described in the SITA P1024 Test Guide (P.Z.1885.3). They also provide facilities for monitoring data on the SLC link and to display the statistics of input and output data.

Two commands are provided for initiating the two functions implemented in CMD:

ZLTST
To perform SITA P1024 tests.

Command format:

ZTLST  OMM(/.../X(YY)
       FMM
       DSS
       ANN
       BNN
       W
       E

Where:

O
On Command

F
Off Command

D
Defer Command

A
Generate Type-A Series NN

B
Generate Type-B Series NN

W
Wait Until Good Data Message Received

E
Terminate Wait

MM
1-2 Digit For Command Number

NN
1-2 Digit For Test Series Number

SS
1-2 Digits For Time In Seconds

X(YY) Optional Parameters

Where:

OM
To Turn On Monitoring On Printer

FM
To Turn Off Monitoring On Printer

ZLKST
To monitor data or to display statistics

Command format:

ZLKST  AI NN CL
       AI LK NN CL

Where:

NN
Symbolic Line Number

CL
Optional Parameter: To Reset Counts To Zero