294 VT1422A Command Reference Chapter 7
FORMat
Note *TST? leaves the instrument in its power-on reset state. This means that
the ASC,7 data format is set even if something else had been set before executing
*TST?. If the FIFO needs to read for test information, set the format after *TST? and
before reading the FIFO.
Related Commands: [SENSe:]DATA:FIFO:?, [SENSe:]DATA:CVTable?,
MEMory subsystem and FETCh?, Also see how DIAG:IEEE can modify
REAL,32 returned values.
*RST Condition: ASCII, 7
After *RST/Power-on, each channel location in the CVT contains the IEEE-754
value "Not-a-number" (NaN). Channel readings which are a positive overvoltage
return IEEE +INF and a negative overvoltage return IEEE -INF. The NaN, +INF
and -INF values for each format are shown in the following table.
Table 7-1. Data Formats
Send with VXIplug&play Function: hpe1422_cmd(...)
Usage FORMAT REAL Set format to IEEE 32-bit Floating Point
FORM REAL, 64 Set format to IEEE 64-bit Floating Point
FORMAT ASCII, 7 Set format to 7-bit ASCII
Format IEEE Term Value Meaning
ASCii +INF +9.9E37 Positive Overload
-INF -9.9E37 Negative Overload
NaN +9.91E37 No Reading
REAL,32 +INF 7F80000016 Positive Overload
-INF FF80000016 Negative Overload
NaN 7FFFFFFF16 No Reading
REAL,64 +INF 7FF000...0016 Positive Overload
-INF FFF000..0016 Negative Overload
NaN 7FFFFF...FF16 No Reading
PACKed,64 +INF 47D2 9EAD 3677 AF6F16 (+9.0e3710) Positive Overload
-INF C7D 2 9EAD 36 77 AF6F 16 (-9.0e3710) Negative Overload
NaN 47D2 A37D CED4 614316 (+9.91e3710) No Reading