Work with communications trace

The Work with communications trace option is only available under system service tools (SST). Select this option from the Start a Service Tool display.

This option allows you to start or stop a communications line trace on a configuration object.

After you run the trace, the data can be formatted. You can view the formatted data by printing it.

Use communications trace for the following situations:
  • To isolate errors that you cannot isolate using the communications verification procedure
  • To collect more data when the problem analysis procedures do not provide enough information on the problem
  • If you suspect a communications protocol violation problem or some other line problem
  • If you suspect line noise
  • When the error messages indicate that there is an SNA BIND problem

Running and interpreting the communications trace requires detailed knowledge of communications protocols. To obtain the most accurate sample of your line status, whenever possible, start the communications trace before varying on the lines.

Note: Online help from the Work with Communications Trace display allows you to view a list of protocols.

Options and function keys

The Work with Communications Traces display has the following options and function keys:
Start trace (F6)
This function key allows you to start tracing the data on a communications configuration object. The Start Trace display appears after you press this function key. For more information, see Starting a trace.
Stop trace (option 2)
This option appears only on the Work with Communications Traces display. It allows you to end the trace and stop collecting data. A trace must be stopped before you can format, print, or delete the data. To ensure that the trace is stopped, press the Refresh function key and check the trace status field.
Delete trace (option 4)
The trace must be stopped (option 2) before you can use this option. Select this option to delete the trace information when you no longer need the data. Traces are not automatically deleted when you leave a communications trace function. Delete trace releases system space so that you can start other traces without having to increase the maximum amount of storage provided for the communications trace. Traces that are not deleted are listed on the Work with Communications Traces display.
Format and print trace (option 6)
Use this option to format and print the trace. For more information on the Format and print trace option, see page Format and print trace.
Display message (option 7)
Use this option to view a message that indicates the status of the trace that stopped because of an error.
Restart trace (option 8)
Use this option to start a trace that has been stopped.
Change size (F10)
Use this function key to change the amount of storage that all traces use. You might want to increase the amount of storage, if your system has many active traces or traces that will be active for a long time.
Display buffer size or display trace status (F11)
This function key allows you to select and alternate between buffer size and trace status.
Refresh (F5)
This function key updates the data on the display.

Status conditions

After the Work with communications trace option is selected from the Start a Service Tool display, the Work with Communications Traces display appears.

Details of the trace, including status, are displayed. The trace status can be one of the following:

Condition description

Waiting
The trace is waiting for the configuration object to be varied on (not collecting data).
Active
The trace data is being collected.
Stopping
The trace is stopping.
Stopped
The trace has stopped (not collecting data).
Error
An error occurred on the configuration object while the trace was collecting data. The data might or might not be collected. The trace stopped.
Starting
The trace is being started by another user. You cannot stop or delete this trace.
Formatting
Trace is being formatted.

Format and print trace

You must select the Stop Trace option before you format or print the trace. The Format and print trace option allows you to select various formatting options and prepare the trace data for printing. The options vary for each protocol. The following is an example of the Format Trace Data display:
Notes:
  1. To view all the data associated with the trace, press Enter without changing the defaults on the Format a Trace Data display. The information is not in any special format.
  2. Select the option to format and print only the data that you want to see.
  3. All options available for formatting depend on the protocol of the line that is being traced.
  4. Not all combinations of options are valid for all protocols.
  5. For more information about these options, use online help.

When the format of the trace data is complete, the output can be printed on the console printer (the printer that is attached to the same I/O processor as the console). Only SCS-type data streams are supported. If IBM® i is available, the trace might be in the job spooled files.

The structure of the trace data is:
  • An introduction page that contains, for example, configuration object, type, protocol, start and stop dates and times, trace options, and formatting options.
  • A help page, to assist in understanding the output. Help information for a specific protocol is given because the trace data differs for each communications protocol.
  • The formatted trace data appears as follows:

The width of the file is 132 characters. The data is in hexadecimal representation and either American National Standard Code for Information Interchange (ASCII) or EBCDIC character representation. The columns of the trace output common to all protocols are:

Record number
The number of the trace record. Shows if the record type is sent (S) or received (R).
Notes:
  1. The letter C in this column indicates that an X.21 short hold mode connection was cleared.
  2. The letter M in this column indicates a modem change has occurred.
Data length
The amount of data, in decimal, that the record contains.
Record status
The protocol-dependent return code for the trace record. 00000000 is successful; no errors were found. Other return codes are listed in the functional specification for the protocol that is running or the port manager.
Record timer
The time that each event occurs. Depending on the communications hardware that is being used, the record timer will be either:
  1. A time of day value, HH:MM:SS.NNNNN (where H=hours, M=minutes, S=seconds, and N=subseconds), based on the system time when the trace was stopped.
  2. A relative time in decimal seconds. This timer value provides the relative time between events.
Data type
Shows whether the traced data is printed in ASCII or EBCDIC character representation. If the character representation of the data is mostly periods, you might want to format the data again using the other option for data representation.
Controller name/number
Indicates which controller originated the frame or record. In some conditions, this data is not available, and the column remains blank.
Note: The formatted trace output is not security protected.
Parent topic: Start a service tool


Last updated: Wed, June 19, 2019