KEPCO BOP 1000W, Operator'S Manual

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BOP-1K 080709
B-21
FIGURE B-7. USING LIST:WAIT COMMANDS TO ALLOW AN EXTERNAL DEVICE TIME TO
FUNCTION WHILE IMPOSING A MAXIMUM WAIT TIME
NOTES: 1. The power supply is assumed to be operating in constant voltage mode.
2. This example assumes a BOP and a DVM is connected to a Unit Under Test (UUT). The DVM is
connected to EXT_E/ EXT_C (pins 5/6 of the BOP External Protection port). When the BOP out-
puts a low EXT_E/ EXT_C, The DVM takes a series of measurements and places its wait line low.
The DVM Wait line is connected to the Trigger Input (pin 3 of the of the BOP. When the Trigger
Input goes high (indicating the DVM has completed its measurements) the BOP will advance to the
next point. For this example it is assumed that the DVM will complete its measurement within 25
milliseconds to 75 milliseconds unless a problem is encountered. A “dead man” timer is imple-
mented that allows up to 99 milliseconds for the measurement to complete before automatically
proceeding to the next point, thereby preventing hang-ups due to a measurement problem.
3. The explanation below shows how each step of the list functions once the list is entered and
VOLT:MODE LIST (the last step) is executed.
list:cle Clear list.
List:set:wait .0333 Set wait time to max allowed value (33 milliseconds).
list:set:trigger .001,ON Set trigger pulse width to 1 millisecond. Transistor across pins 5 and 6
of External Protection Port is now set off.
list:volt:apply level,.001,10 Create first point (10V).
list:dwell:points? Returns 10.
list:trigger 10 Maintains output at 10V, generates a 1 millisecond 0V trigger pulse
applied to DVM, causing DVM to make measurement.
Trigger input low while DVM makes measurement.
list:wait:high 10
Wait for DVM to complete measurement for 33 milliseconds. Proceed to
next step if trigger input goes high (meaning the measurement is com-
plete) or 33 milliseconds elapsed, whichever comes first.
Trigger input low while DVM makes measurement.
list:wait:high 10
Wait for DVM to complete measurement for another 33 milliseconds.
Proceed to next step if trigger input goes high (meaning the measure-
ment is complete) or 33 milliseconds elapsed, whichever comes first
Trigger input low while makes measurement.
list:wait:high 10
Wait for DVM complete measurement for another 33 milliseconds
(these three steps allow a maximum wait time of 99 milliseconds. Pro-
ceed to next step if trigger input goes high (meaning the measurement
is complete) or 33 milliseconds elapsed, whichever comes first.
list:repeat 10,13,20,30,40,50,60,70,80,90 Repeats steps 10 through 13 (from list:apply level to the third
list:wait:high 10) for the other 8 voltages (20, 30, . . . 90).
list:count 10 Repeat sequence ten times.
curr 2;:outp on Establishes BOP output current of 2A.
volt:mode list Executes the above list. A level is applied to the BOP output. One 1 mil-
lisecond later the transistor at EXT_E and EXT_C (pins 5 and 6 of the
External Protection Port) conducts, providing a low to the DVM. The
DVM immediately places the BOP trigger input low. The BOP waits for
the trigger input to go high, then outputs the next level in the list. If the
trigger input never goes high, the three wait statements will maintain the
level for 33 milliseconds each. After 99 milliseconds (three wait state-
ments) has expired, the new voltage level will be provided at the output.
In this example, the pulse must be less than 1 millisecond. but at least
50 microseconds long to insure proper operation of the program.