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For the C programming language, you can declare a structure 

typedef

 to 

store the parameters of 

ncOpenDnetIO

, similar to the following:

typedef struct {

NCTYPE_UINT32DeviceMacId;

NCTYPE_CONN_TYPEConnectionType;

NCTYPE_UINT32InputLength;

NCTYPE_UINT32OutputLength;

NCTYPE_UINT32ExpPacketRate;

} OpenDnetIO_Struct;

For LabVIEW, a cluster that contains these parameters is already defined 
for use with 

ncOpenDnetIO

.

You can use this structure/cluster to declare an array that contains one entry 
for each call you make to 

ncOpenDnetIO

. In LabVIEW and 

LabWindows/CVI, you can use front panel controls to index through this 
array and update configurations as needed.

In your code, write a For loop to index through the array and call 

ncOpenDnetIO

 once for each array entry. This simplifies your code 

because it does not contain a long list of sequential open calls, but instead 
all open calls are combined into a concise loop.

If you use an array to store configuration parameters for 

ncOpenDnetIO

, 

you can use this same scheme to store the 

ObjHandle

 returned by 

ncOpenDnetIO

. Within the For loop used for 

ncOpenDnetIO

, you can store 

the resulting 

ObjHandle

 into an array of object handles. Throughout your 

code, you can index into this array to obtain the appropriate object handle.

Using an array of object handles is particularly useful in the LabVIEW 
programming environment because it eliminates confusing routing of 
individual object handle wires.

For applications with only a few object handles, another useful technique 
for LabVIEW is to store each object handle in an indicator, then create a 
local variable for each call that uses the handle. To create the indicator, 
right-click on the 

ObjHandle out

 terminal and select Create Indicator. 

To create a local variable, right-click on the indicator, select Create»Local 
Variable, right-click on the local variable, and select Change To Read 
Local. For more information on local variables, refer to the LabVIEW 
online reference.