The Model 224 is a programmable current source with full range current output of 20,uA to 101 mA. The smallest step of output current is 5nA. The Model 224 has a selectable voltage compliance of up to 105V in IV increments. The value of output current can be modified in two ways: manually or automatically. The automatically modified current value is incremented or decremented by the programmed rate. The time button allows the modification of the programmed auto increment/decrement rate. The control of the current value modification can be activated by an external trigger pulse applied to the EXTERNAL TRIGGER INPUT. At the completion of the current value modification (each digit) the Model 224 outputs a pulse that has the specifications shown in Figure 2-5. This pulse can be used to trigger another instrument (printer, DMM, controller, etc.1 to start its programmed task. With the Model 2243 IEEE-488 interface option installed, the Model 224 can be used with any measurement system that uses ?he IEEE-488 bus. For detailed operating instructions of the Model 2243 IEEE-488 interface option, refer to the Model 2243 Instruction Manual