VXI VT1422A - Manual (Page 337)

VT1422A Command Reference 335 Chapter 7
[SENSe]
[SENSe:]DATA:FIFO:HALF?
[SENSe:]DATA:FIFO:HALF? returns 32,768 values if the FIFO buffer is at least
half-full. This command provides a fast means of acquiring blocks of values from
the buffer.
Comments •
For acquiring data from continuous scans, an application needs to execute a
DATA:FIFO:HALF? command and a read statement often enough to keep up
with the rate that values are being sent to the FIFO.
•
Use the DATA:FIFO:ALL? command to acquire the values remaining in the
FIFO buffer after the ABORT command has stopped execution.
•
The format of values returned is set using the FORMat[:DATA] command.
•
Returned Value: ASCII values are returned in the form
±1.234567E±123.
For example 13.325 volts would be +1.3325000E+001. Each value is followed
by a comma (,). A line feed (LF) and End-Or-Identify (EOI) follow the last value.
The data type is a string array.
REAL 32, REAL 64, and PACK 64, values are returned in the IEEE-488.2-1987
Definite Length Arbitrary Block Data format. This data return format is
explained in “Arbitrary Block Program and Response Data” on page 233.
For REAL 32, each value is 4 bytes in length (the data type is a float32 array).
For REAL 64 and PACK 64, each value is 8 bytes in length (the data type is a
float64 array).
Note
Values which are a positive overvoltage return IEEE +INF and a negative overvoltage
return IEEE -INF (see Table 7-1 on page 294 for actual values for each data format).
•
Related Commands: DATA:FIFO:COUNT:HALF?
•
*RST Condition: FIFO buffer is empty
•
Send with VXIplug&play Function: hpe1422_readFifoFast_Q(...)
Command
Sequence
DATA:FIFO:COUNT:HALF?
poll FIFO for half-full status
DATA:FIFO:HALF?
returns 32768 values