Deleting traces, Buffered (memory) input – Agilent Technologies L4400 User Manual
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L4400 User’s Guide
8
L4450A 64-Bit Digital I/O with Memory and Counter
If the trigger source has been set to one of the interrupt lines (see page
), the output will wait for the interrupt to occur and then the
handshake to occur before the trace is output.
You can also output the trace one sample at a time on the data lines using
the
SOURce:DIGital:MEMory:STEP
command. This command outputs one
sample and then puts the memory in the stopped state. The STEP
command also overrides the interrupt line so it can be used to trigger a
transfer even if the interrupt line is set to be the trigger source.
Deleting Traces
You can delete traces in memory to recover the memory space. Use the
TRACe:DELete:NAME
command to delete a specific trace. Note that deleting
a specific trace does not de- fragment the memory. You can delete all
traces using the
TRACe:DELete:ALL
command.
Buffered (Memory) Input
Each bank on the L4450A has its own memory for use in buffered
transfers. Changing a bank from an output to an input will clear all
memory for that bank. The general steps to use input memory are:
1
Set the channel width and parameters.
2
Set the handshake mode.
3
Set the number of samples to collect.
4
Start the capture.
5
Check the status of the transfer.
6
Retrieve the captured data.
Set the channel width and direction. Use the
CONFigure:DIGital
command
to set the channel width, direction, thresholds, and polarity. See
for basic input operations.
Set the handshake mode. You must use synchronous handshaking mode.
Handshaking is described in more detail on
Set the number of samples to collect. The
SENSe:DIGital:MEMory:SAMPle:COUNt
command sets the number of samples
to capture. If you set the number of counts to infinite (0 = default), the
bank will capture data until a STOP is received. Older samples are
overwritten if memory gets full. Allowed sample counts depend upon the
channel width as follows:
• BYTE (8- bit) 1 to 65535
• WORD (16- bit) 1 to 65535
• LWORd (32- bit) 1 to 32767