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OMI - Device Ownership

Draft MDC Standard

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B.8 Device ownership

ANSI/MDC X11.1 specifies how M[UMPS] processes deal with devices. Refer to it for details of the information that OMI's device transactions carry between client and server.

An M[UMPS] process establishes ownership of 1 or more devices by means of OPEN commands that may optionally set devices' parameters. The get device parameters and open device transactions support the OPEN command.

Data and control are directed to just 1 of the open devices, called the current device, selected by the USE command. OMI needs no direct support for USE because each transaction carries the device's name. Therefore the server need not keep track of the client's current device.

However, the USE command and also the CLOSE command may optionally set a device's parameters. The set device parameters transaction supports them.

The M[UMPS] process retains ownership of its devices until it executes a CLOSE command or until it terminates. The three close transactions support relinquishing device ownership.

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Copyright © Standard Documents; 1977-2018 MUMPS Development Committee;
Copyright © Examples: 1995-2018 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2018 Ed de Moel.

Some specifications are "approved for inclusion in a future standard". Note that the MUMPS Development Committee cannot guarantee that such future standards will indeed be published.

This page most recently updated on 07-Mar-2004, 13:32:52 .

For comments, contact Ed de Moel (demoel@jacquardsystems.com)