VXi VT1422A 사용자 설명서

To specify that values are to remain in IEEE 32-bit Floating Point format for 
fastest transfer rate:

FORMAT REAL,32

To specify that values are to be converted to 7-bit ASCII and returned as a 
fifteen character per value comma separated list:

FORMAT ASC,7

     

or

FORM ASC

The VT1422A’s FIFO can operate in two modes. One mode is for reading 
FIFO values while the VT1422A is scanning and/or running algorithms; the 
other mode is for reading FIFO values after operation have been halted 
(ABORT sent). 

•

 BLOCking: The BLOCking mode is the default and is used to read the 

FIFO while algorithms are executing. The application program must 
read FIFO values often enough to keep it from overflowing (See 
“Continuously Reading the FIFO (FIFO mode BLOCK)” on page 135.). 
The FIFO stops accepting values when it becomes full (65,024 values). 
Values sent after the FIFO is full are discarded. The first value to 
exceed 65,024 sets the STAT:QUES:COND? bit 10 (FIFO Overflowed) 
and an error message is put in Error Queue (read with SYS:ERR? 
query).

•

OVERwrite: When the VT1422A is running and the FIFO fills, the 

oldest values in the FIFO are overwritten by the newest values. Only 
the latest 65,024 values are available. In OVERwrite mode the module 
must be halted (ABORT sent) before reading the FIFO (See “Reading 
the Latest FIFO Values (FIFO mode OVER)” on page 137.). 
This mode is very useful when viewing an algorithm’s response to a 
disturbance is desired.

To set the FIFO mode (blocking is the *RST/Power-on condition):

[SENSe:]DATA:FIFO:MODE OVERWRITE

[SENSe:]DATA:FIFO:MODE BLOCK