DAQV Procedures

Any arrays to be visualized must be registered with DAQV via the DAQV_REGISTER() routine. In this sample program the array D is registered twice (on lines 20 and 21). The array is registered twice so that it may be visualized using two different data clients. The call to DAQV_REGISTER() gives DAQV important information about the array, including data type, rank, and size. DAQV_REGISTER() returns an ID that the programmer uses when referring to the array later in the program.

DAQV_PULL_ENABLE() and DAQV_PULL_DISABLE() are used to activate regions of the code during which DAQV should operate. Minimally, a single call to DAQV_PULL_ENABLE() is required to activate DAQV (i.e., wait for a connection from the control client). Use of the disable routine is optional and is provided as a convenience to the programmer. In a long-running code, for example, a programmer may only want to examine array values over the life of a specific loop. By placing the enable/disable calls around that loop, the overhead associated with using DAQV will be greatly diminished in the other parts of the code. DAQV can be activated and deactivated arbitrarily during the program. The call to DAQV_PULL_ENABLE() is on line 23. When the compiled program is executed on the command line, the code runs normally until the the DAQV_PULL_ENABLE() routine is encountered, at which point DAQV is activated and requires an external control client to connect. At this point in the tutorial, line 25 is highlighted, this indicates that the program is stopped here after the connection is made between the client and server.

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