You can obtain information
on controller characteristics by using the Get Device/Volume Information
($GETDVI) system service. (See the HP OpenVMS System Services
$GETDVI returns controller characteristics when
you specify the item code DVI$_DEVCHAR. Table 9-25 lists these characteristics, which are defined
by the $DEVDEF macro and in the file SYS$LIBRARY:DEVDEF.H.
Table 9-25 Ethernet Controller Device Characteristics
| || Static Bits (Always Set) |
Device is available.
DVI$_DEVTYPE and DVI$_DEVCLASS return the device
type and device class names, which are defined by the $DCDEF macro
and in the file SYS$LIBRARY:DCDEF.H. The device class name for the
LAN Ethernet controllers listed in “Supported LAN Devices” is always DC$_SCOM.
the maximum message size. The maximum send or receive message size
depends on the packet format and whether padding (NMA$C_PCLI_PAD)
is enabled (see “Read” and “Write” ). DVI$_DEVDEPEND returns the unit and line status bits and the
error summary bits in a longword field as shown in Figure 9-11.
Figure 9-11 DVI$_DEVDEPEND Returns
Table 9-26 lists the status values and their meanings. These values are defined
by the $XMDEF macro. XM$M_STS_ACTIVE is set when the port is started.
XM$M_STS_BUFFAIL and XM$M_STS_TIMO are dynamically set and cleared
by the LAN driver.
Table 9-26 Ethernet Controller Unit and Line Status
Port is active.
Attempt to allocate a
system receive buffer failed.
The error summary bits are set when an error occurs.
They are read-only bits. If an error is fatal, the Ethernet port is
shut down. Table 9-27 lists
the error summary bit values and their meanings.
Table 9-27 Error Summary Bits
|Error Summary Bit||Meaning|
Hardware or software error occurred
on the controller.