Echelon OpenLDV - Manual (Page 43)

OpenLDV Programmer’s Guide 35
Table 20. ldvx_open() Parameters
Parameter Direction Description
id Input The L ON W ORKS interface device with which to establish
communication. For example, “LON1” could be used to
identify a U10, PCLTA-10, or PCLTA-21 network interface.
Or, “X.Default.1MainStreet” could be used to identify a
SmartServer that will be opened through xDriver.
handle Output A pointer to a variable that you can use to identify the
network interface with the other OpenLDV functions. This
handle is valid only if the function returns LDV_OK.
hWnd Input The Windows handle for the session state change or
attachment notification messages, where available (for
example, from an xDriver device or a USB network
interface).
If NULL, no notification messages are sent.
See Windows Messages for Session Notifications on page 44.
tag Input Correlates notification messages with sessions. This tag is
supplied as the LPARAM parameter of all session state
change messages.
Remarks
This function is an extended version of the ldv_open() function that additionally
allows you to specify a Windows handle and tag for session state change or
attachment notificatgion messages. This function returns LDV_OK if the
network interface is successfully opened. In this case, the function also returns a
handle that you can use to identify the network interface with the other
OpenLDV functions. You can use the ldv_close() function to close the session
with the network interface.
For local network interfaces, after the ldvx_open() function returns the
LDV_OK success code, the network interface device has been initialized (see
below for information about remote network interfaces). For some network
interface types, the network interface enters an initial quiet mode (flush state)
after reset. To start using the network interface, the OpenLDV application must
cancel the flush state with the niFLUSH_CANCEL immediate network
interface command. For more information about immediate commands, see
Immediate Commands on page 77.
Each successful ldv_open(), ldv_open_cap(), or ldvx_open() call (including
nested ones) must have a matching ldv_close() call.
For xDriver-based remote network interfaces that use the default xDriver lookup
extension, the name specified as the id parameter must match an entry created
for a device with the L
ON
W
ORKS
Interfaces application in the Windows Control
Panel. See Chapter 5, Using the xDriver Default Profile, on page 93, for more