VME (VXI data transfer) Bus transfers

 

When data is transferred over the VME bus directly from the A/D converter, a read

 

of VME A24 address space, offset 12 (0C16), causes a measurement to be taken and

 

transferred all in the same read cycle. During the read cycle, the

 

HP E1429 takes a reading and puts the data into the register before the read cycle

 

completes. The ARM sources may be set to any legal source for this mode, but

 

TRIGger:START:SOURce must be set to VME. Selections can be made using the

 

VINStrument:CONFigure:VME:FEED command such that a single read produces

 

data from only one channel (16 bits), or both channels simultaneously (32 bits).

 

When the data is transferred post measurement, completion of the

 

INITiate:IMMediate command will automatically configure for a VME transfer

 

from memory, based on the settings of the VINStrument:VME:FEED command.

 

When the measurement has completed and the VME transfer has been set up by the

 

HP E1429, bit 1 (Memory Read Enable) of the A24 memory control register (base +

 

2116) will go high (1). At this point, data transfer can be initiated by the receiver by

 

reading the A24 data register (base + 0C16). Again, the VINStrument:VME:FEED

 

command is used to specify whether a single read will produce one channel (16 bits)

 

of data, or two channels (32 bits) of data. The

 

VINStrument:VME:MEMory:INITiate command will also configure for a post

 

measurement VME data transfer, but it need not be sent unless it is desirable to read

 

the same data multiple times.

 

Subsystem

VINStrument

 

Syntax

[:CONFigure]

 

 

:LBUS

 

 

:FEED <source >

 

 

:MEMory

 

 

:INITiate

[no query]

 

[:MODE] <mode >

 

 

:RESet

[no query]

 

:SEND

 

 

:POINts <count >

 

 

:AUTO <mode >

 

 

:TEST

 

 

:DATA <voltage_list >

[no query]

 

:VME

 

 

:FEED <source >

 

 

:MEMory

 

 

:INITiate

[no query]

 

[:MODE] <mode >

 

 

:SEND

 

 

:ADDRess

 

 

:DATA?

[query only]

 

:IDENtity?

 

284 Command Reference

VINStrument Subsystem

Page 284
Image 284
HP E1429A manual VME VXI data transfer Bus transfers, Data voltagelist