Agilent Technologies 5741A Output On/Off Controls, OUT on button, Safe-Start and Auto-Restart

3 Operating the Power Supply Locally

Output On/Off Controls

The Output On/Off controls turn the power supply output on or off. This can be done with the front panel OUT ON button or from the rear panel J1 connector. With the output off, adjustments can be made to the power supply or the load without shutting off AC power.

OUT ON button

The OUT ON button can be pressed at any time to enable or disable the power supply output. When the output is disabled, the output voltage and current go to zero and the display shows OFF.

Safe-Start and Auto-Restart

The power supply can be programmed to have either the last operating settings (Auto-Restart) or the reset settings (Safe-Start) apply at turn-on. Press and hold the OUT ON button to select between Safe-Start and Auto-Restart modes. The display continuously cycles between SAF and AUT every three seconds. Releasing the OUT ON button while one of the modes is displayed, selects that mode.

In Safe-Start mode, the power supply turns on with the reset settings (see chapter 5 under “*RST”). The output is disabled and the output voltage and current are zero. This is the factory default.

In Auto-Restart mode, the power supply restores the operating settings that were saved when it was last turned off (see below). The output is either enabled or disabled according to its last setting.

Output On/Off state	UVL level
Output voltage setting	OCP setting
Output current setting	Locked/Unlocked front panel
OVP level	Start-up mode

Output Shut-Off Terminals

Output Shut-Off (SO) terminals are available on the J1 connector to enable or disable the power supply output. This function is edge- triggered. J1 pin 15 is the Shut-Off input, and pins 2 and 3, which are connected internally, are the signal common. All pins are optically isolated from the power supply output. The Shut-Off input accepts a 2.5V-to-15V signal or an open/short contact to enable or disable the output. The Shut-Off control logic is selected by SW1 setup switch 5.

When an on-to-off transition is detected at the Shut-Off input, the Shut-Off function enables or disables the output according to the signal level or the open/short applied to J1 pin 15. When the output has been disabled by the Shut-Off function, the display shows SO to indicate the output is disabled.

40 Series N5700 User’s Guide