4-24
BIT 4886 051010
4.7.4.1
CALIBRATION STORAGE
The BIT 4886 maintains the calibration tables in Flash Memory until a PACK is executed. There
are six calibration areas maintained in Flash Memory: Working, Prior, Oldest, Factory, Master,
and First.
The calibration can be copied to another area using the CAL:COPY command. The syntax is as
follows: CAL:COPY (source) (destination) where (source) and (destination) refer to the areas of
Flash memory where calibration data is stored, designated as: WORKing, PRIor, OLDest, FAC-
Tory, MASTer, FIRst. Source refers to the calibration area that is to be copied, destination to the
area that the calibration will be copied into.
DIAG:LEADING xx
(xx is the time in half mil-
liseconds increments)
(hex)
DIAG:LEADING?
returns xx (hex), the
time in half millisec-
onds increments)
xx establishes max dwell time for a two-step list. If the dwell time DD for the two-
step list exceeds xx, a step is inserted with voltage = 0V for (DD - xx). MSTS
default = 50.
Consider the following:
LIST:VOLT 0,5
Two step list, 0V then 5V.
LIST:DWEL .05
Dwell time of 50 ms
LIST:COUNT 0
Repeat continuously.
OUTP ON
Output enabled.
VOLT:MODE LIST
Run program
The above list would normally produce a continuous square wave, 50ms at 0V,
50mS at 5V (Fig A). If DIAG:LEADING 50 (40 ms) is issued, the square wave
changes to 60ms at 0V, 40mS at 5V as follows: the first 1/2 cycle = 50mS at 0V,
the second 1/2 cycle = 40mS (the limit set by DIAG:LEADING) at 5V, then 10mS
(50 - 40 = 10) at 0V (Fig B). If LIST:VOLT 0,5 is changed to LIST:VOLT -5,5 both
1/2 cycles will show 10mS steps at 0V (Fig C).
1
The default window value of 32 indicates a 32 LSB margin for error during readback. The value for Readback is arrived at by taking
16 samples of voltage or current and averaging them. A readback error is produced when the calculated readback value (with cali-
bration constants applied) exceeds the maximum readback (calculated re error window) or minimum readback (calculated
readback – error window). Increasing the error window can avoid undesired errors. For example, in cases where the LIST command
is used to produce a square wave output, overshoot inherent in the characteristics of the power supply can sometimes cause the
readback average to increase enough to cause a readback error. Increasing the error window allows the square wave to be gener-
ated without producing an error.
TABLE 4-5. ENHANCED OPERATION - ERROR RESPONSE (CONTINUED)
COMMAND
QUERY
DESCRIPTION
