Dc Isolated Input Signals; Circuit Con Guration Of Control Output Signals - Agilent Technologies 4286A User Manual

Figure 4-11. Circuit Con guration of Control Output Signals

DC Isolated Input Signals

DC isolated input signals can be divided into /EXT TRIG and /KEY LOCK.
/EXT TRIG
/EXT TRIG (pins 12 and 13) is input to the cathode of photocoupler LED. The 4286A is
triggered at the falling edge or rising edge of pulse, which can be selected through 4286A's
softkey setting. Drive voltage is applied to the anode of photocoupler LED by the internal
(5V) or external (EXT.DCV2) power source. (Use switches on the handler interface board to
select the desired source.)
Note
Use SW2 to select the proper resistor according to the level of anode voltage
applied. This resistor is used to limit the trigger voltage to the speci ed level.
See Table 4-5 for details.
/KEY LOCK
/KEY LOCK(pin 25) is input to the cathode of photocoupler LED. All keys on the 4286A
front panel are disabled when this signal is low. Drive voltage is applied to the anode of
photocoupler LED through pins 14 and 15 by the internal (5V) or external (EXT.DCV2) power
source. (Use switches on the handler interface board to select the desired source.)
4286A with Chip Handler 4-35