devs file

The devs file defines the various devices in the system.


This file, located on the dm account, has two data levels:

  • The init data level contains static information that can be changed by the System Administrator to set up the various entities in the system. For example, the initial baud rate of the serial ports, whether tandem is allowed on the D3 ports or not, can be specified in this data level. It contains an item for all possible elements in the system, even if they are not physically present.

  • The devs data level contains dynamic information. The TCL command reset-async, normally runs at boot time in the system-coldstart macro, clears the devs,devs, file and copies the information from devs,init into devs,devs. Only the physically present system elements are represented in this file. Writing an item into this data level programs the device.

For UNIX: Items in this file may be added or removed with the dev-make or dev-remov TCL commands.

For Windows: Not supported.

The item-IDs in this file are the entity-IDs, which are composed of a one letter code p for D3 ports, s for serial device, e for Ethernet, and so on), followed by the entity number in decimal (the D3 port number, the serial device number, the TCP/IP connection-ID, and so on).

Both data levels can be examined using AQL or the Update processor. The structure of an item in these files is described in the include dm,bp,includes


Examines the characteristics of serial device 12, opens the Update processor, and allows changing the initial setting of the serial device. Filing this item does not actually change the setting. It is changed the next time the reset-async command is run (normally at boot time) or by running the reset-async s12 command.

u devs,init s12

Examines the characteristics of D3 port 0. The only element than can be changed is the tandem flag, which controls whether or not tandem is allowed on port 0, and whether the target process should be notified about the tandem on/off.

u devs p0

Show the current status of all serial ports.

sort devs = "s]"