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LAN Device Information  



You can obtain information on controller characteristics by using the Get Device/Volume Information ($GETDVI) system service. (Refer to the HP OpenVMS System Services Reference Manual.)

$GETDVI returns controller characteristics when you specify the item code DVI$_DEVCHAR. Ethernet Controller Device Characteristics lists these characteristics, which are defined by the $DEVDEF macro and in the file SYS$LIBRARY:DEVDEF.H.

Table 31   Ethernet Controller Device Characteristics
Characteristic Meaning

Static Bits (Always Set)
DEV$M_AVL
Device is available.
DEV$M_IDV
Input device.
DEV$M_NET
Network device.
DEV$M_ODV
Output device.

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 OpenVMS VAX LAN Devices and OpenVMS Alpha LAN Devices is always DC$_SCOM.

DVI$_DEVBUFSIZ returns the maximum message size. The maximum send or receive message size depends on the packet format and whether padding (NMA$C_PCLI_PAD) is enabled (see Sections Read and Write ). DVI$_DEVDEPEND returns the unit and line status bits and the error summary bits in a longword field as shown in DVI$_DEVDEPEND Returns.  

Figure 11  DVI$_DEVDEPEND Returns  
DVI$_DEVDEPEND Returns

Ethernet Controller Unit and Line Status 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 32   Ethernet Controller Unit and Line Status
Status Meaning
XM$M_STS_ACTIVE
Port is active.
XM$M_STS_BUFFAIL
Attempt to allocate a system receive buffer failed.
XM$M_STS_TIMO
Timeout occurred.

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. Error Summary Bits lists the error summary bit values and their meanings.

Table 33   Error Summary Bits
Error Summary Bit Meaning
XM$M_ERR_FATAL
Hardware or software error occurred on the controller.


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