AUTOMON/VTAM eliminates superfluous characters in data streams that are transmitted to and from the host CPU and terminals.
Since the number of characters in a data stream is the major factor in determining the response time for an on-line transaction, the elimination of extra characters can significantly reduce that time. Most users experience a 55 to 80% reduction in terminal traffic with AUTOMON/VTAM, which results in dramatic savings both in time and cost of the computer installation usage.
With AUTOMON/VTAM you can have data stream compression for any VTAM application. CICS, IMS, TSO, any application system which communicates with terminals using VTAM can benefit. It does not require its own region or partition to operate. AUTOMON/VTAM will increase efficiency of mission critical domains such as CICS, IMS/DC, TSO, ROSCOE, IDMS/DC, printers, terminals, PCs, third party hardware and applications.
Today's network system programmer, for the most part, only has control over the first of these variables, overall system tuning. They can distribute the load over the available resources to maximize efficiency and adjust the various application controls to eliminate bottlenecks. They can do very little in most conditions, to control application program efficiency or data transmission amounts, since much of today's application software is made up of vendor-written packages.
The average outbound terminal data stream contains 20 to 25 percent character repetition, transmitting more data on every transaction than is necessary and making application software severely inefficient.
Terminal data stream compression at the VTAM level.
Repetitive character elimination
Transmission of only the changed data
Inbound mirroring
Threshold table
Selection list
Exclusion list
User exit handler and a TSO command driver
An image in outbound compression of each terminal buffer is maintained in memory.
Image saved in memory
The saved image is always an exact replica of what is displayed on the terminal at any given time. When an output data stream is sent to the terminal, AUTOMON/VTAM compares the outgoing image with the image of the buffer.
Elimination logic
When AUTOMON/VTAM detects the outgoing data stream is an entirely different screen display, repetitive character elimination is performed on the data stream and sent to the terminal, leaving the ERASE command undisturbed.
Remove ERASE command
When the outgoing data stream contains many of the title and text fields currently in the image of the terminal buffer, AUTOMON/VTAM removes the ERASE command, making it a data-only write.
Remove already present fields
AUTOMON/VTAM also removes all fields in the outgoing data stream that are already present on the terminal screen. Even the data fields are examined and removed if the same data is being sent again.
Reduce the total amount of data transmitted from the terminal.
Modified data tag
When data is entered into any field on the screen, logic contained in the terminal causes a flag to be turned on in the attribute byte of that field, indicating that the field was modified. This flag is called the modified-data-tag:use of, or MDT.
MDT application activation
The MDT can also be turned on by an application program when the data stream is transmitted to the terminal. If this is done, the field will be transmitted back from the terminal, whether the operator enters anything in that field or not.
Reduce transmitted data
AUTOMON/VTAM reduces the amount of data transmitted from the terminal by turning off all modified-data-tag:removal ofs as the data streams:inbound is going out to the terminal. Therefore, only data that is actually modified is transmitted back in.
Intelligent field insertion
When fields don't come back in, AUTOMON/VTAM inserts them into the data stream prior to sending it on to the application system. As a result, when the application program receives the input data, it looks exactly as it would normally appear.