Single Digitizer In a single digitizer configuration, the digitizer is usually the data generator and a device such as the HP E1488 memory card is the consumer. With this configuration, the programming sequence is:

1.Use the CONFigure command and the low-level digitizer commands to configure the digitizer for the required measurements.

2.Use the VINStrument subsystem to reset the digitizer’s Local bus chip, to set the Local bus transfer mode (generate), and to set the data source (post measurement or real time transfer).

VINStrument:CONFigure:LBUS:RESet VINStrument:CONFigure:LBUS:MODE <mode> VINStrument:CONFigure:LBUS:FEED <source >

3.Reset the consumer’s (i.e. memory card’s) Local bus chip and configure the consumer to receive data.

4.Activate (initiate) the consumer.

Multiple Digitizers and Serial Transfers

5.Use INITiate:IMMediate to activate the digitizer and start reading transfers.

In a configuration with two or more digitizers transferring data serially, the leftmost digitizer is set to the generate mode and the succeeding digitizer(s) is set to either the append mode or the insert mode. A device such as the HP E1488 memory card is usually the consumer.

In a serial transfer, each digitizer transfers data from its memory or directly from its A/D in sequence. For example, serial transfers from digitizers D1 - D3 where D1 is in generator mode and D2 and D3 are in append mode would appear as:

EOF EOB D3 D3 D3

EOB D2 D2 D2

EOB D1 D1 D1 -----> consumer

When D1 is in generator mode and D2 and D3 are in insert mode the transfer sequence would appear as:

EOF EOB D1 D1 D1

EOB D2 D2 D2

EOB D3 D3 D3 -----> consumer

In these sequences, EOF is the end-of-frame flag, EOB is the end-of-block flag, and Dn is either a two byte (one channel) or four byte (two channel) reading. The procedure for a serial transfer is:

160 Understanding the HP E1429 Digitizer

Chapter 3

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HP E1429A manual Multiple Digitizers and Serial Transfers, EOF EOB D3 D3 D3, EOF EOB D1 D1 D1