B&K Precision 8500-8526 - Manual - Manual (Page 42)

Keys Display
another test run or press Esc to return to the normal display.
Esc Return to the normal display.
Triggering
Triggering is used with the transient and dynamic conditions to allow synchronization of the DC
Load's behavior with other events. There are three types of triggers you may use (set in the
CONFIG:TRIGGER SOURCE menu):
Trigger Type Explanation
IMMEDIATE An immediate trigger is created by pressing Shift + Trigger on the
front panel keys.
EXTERNAL An external trigger is a TTL high signal applied to the Trigger
connection on the back panel. This TTL signal must last for more than
5 ms. A trigger applied to this input can be used to change settings
(voltage, current , resistance), toggle between settings in transient-
toggle mode, or generate a pulse in pulse mode.
BUS The instrument will be triggered if a 5AH command is sent via the RS-
232 interface. See the Remote operation section for more details.
Voltage threshold operation
The DC Load can be set to only turn on if the voltage is at or above a set value. Additionally, the
load will turn off if the voltage drops below a second set value. This feature works for any mode.
An example of use would be to ensure an electronic system under test will not have power applied
unless the supply voltage is above a certain value. The DC Load would be put in series with the
power supply. Remote sensing would be turned on and the remote sensing connector on the back
would be used to connect to the power supply's output voltage.
Use the menu items SYSTEM SET:VOLTAGE ON SET and SYSTEM SET:VOLTAGE OFF SET to
set the on and off voltage thresholds, respectively.
Example
1: set the VOLTAGE ON SET and SYSTEM SET:VOLTAGE OFF SET both to 1.0 V.
Set the instrument to constant current mode with the I-set key and set the current level to 0.1 A.
Turn the load on by pressing the On/Off key. When power is applied to the DC Load, the voltage
must rise above 1.0 V before the load draws current from the source. If the voltage drops below 1.0
V on the load's terminals, the load will stop drawing current from the source.
Example 2: Same as the previous example, except set the VOLTAGE ON SET to 1.0 V and the
SYSTEM SET:VOLTAGE OFF SET 0.0 V. As before, the load will turn on only when the voltage
exceeds 1.0 V, but once it is "triggered" on, it will now stay on, even if the voltage drops to zero.
Passwords
If you enter the menu CONFIG:KEY LOCK SET, you can set a one to four digit password. This
password will be required when changing settings from the front panel. The only operations allowed
without entering the password are:
8500 DC Load Series Version: 030614 Page 42 of 77