Browse Prior Art Database

Multiplex Meter

IP.com Disclosure Number: IPCOM000079191D
Original Publication Date: 1973-May-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Ballou, DC: AUTHOR

Abstract

When attaching to IBM System/360 or IBM System/370 multiplex channels, a control unit must transfer data in bursts that consume less than 32 microseconds of control unit time, to qualify as a multiplex-mode device. Most control units logically connect to the channel, transfer a set number of bytes of data, then logically disconnect.

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Multiplex Meter

When attaching to IBM System/360 or IBM System/370 multiplex channels, a control unit must transfer data in bursts that consume less than 32 microseconds of control unit time, to qualify as a multiplex-mode device. Most control units logically connect to the channel, transfer a set number of bytes of data, then logically disconnect.

This multiplex meter allows the control unit to transfer as many bytes as possible within the 32 microsecond limit, rather than a preset number of bytes. Control units with variable-data rates, different rates for different commands, high-data rates or multiple devices with different data rates can be attached to the multiplex channels with maximum efficiency.

This device can be added to existing control units with minimum of change. The multiplex meter is readily adapted to specific control units and can be used to control data transfer both to and from the channel.

Referring to the drawing, AND's 2-7 state when the meter should not be running; it is more difficult to monitor when the meter should run. AND's 2 and 3 are used exclusively for the extended bus feature of S/370 and can be removed if this feature is not used. If the selection sequences are fast and most metered time occurs during data transfer, count only the data transfer time (AND's 6 and
7). In this case, the meter should time-out somewhat earlier to account for the selection sequence. The designations of the signals at the inputs of AND's 1-8 follows t...