HP E1432A User's Guide

Using the HP E1432A

￿Calling hpe1432_createChannelGroup to delete a group that is simultaneously being used by non-interrupt-handler code.

￿Calling one of the read data functions (hpe1432_readRawData or

hpe1432_readFloat64Data), if the non-interrupt-handler code is also calling one of these functions.

￿Calling hpe1432_init to reset the list of channels that are available to the HP E1432A library.

As is always the case with interrupt handlers, it is easy to introduce bugs into your program, and generally hard to track down these bugs. Be careful when writing this function.

Data Gating

Sometimes you may wish to monitor data from some input channels and not others. The function hpe1432_setEnable enables or disables data from an input channel (or group of channels). If data is enabled, then the data can be read using hpe1432_blockAvailable and hpe1432_readRawData or hpe1432_readFloat64Data. If data is disabled, data from the specified channel is not made available to the host computer.

This parameter can be changed while a measurement is running, to allow the host computer to look at only some of the data being collected by the HP E1432A module. While data from a channel is disabled the input module continues to collect data but it is not made available to the host computer. The host can then switch from looking at some channels to looking at others during the measurement. In contrast, the function hpe1432_setActive completely enables or disables a channel and can’t be changed while a measurement is running.

For order tracking measurements this function can be used to switch between receiving order tracking data, ordinary time data, or both.

HP E1432A Parameters

Some parameters, such as range or coupling, apply to specific channels. When a channel ID is given to a function that sets a channel-specific parameter, only that channel is set to the new value.

Some parameters, such as clock frequency or data transfer mode, apply globally to a module. When a channel ID is used to change a parameter that applies to a whole module, the channel ID is used to determine which module. The parameter is then changed for that module.

Starting and stopping a measurement is somewhat like setting a global parameter. Starting a measurement starts each active channel in each module that has a channel in the group.

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