To enable an output after it went into overvoltage, you must first remove the overvoltage condition and then send the OV reset command.

To reset output 1 send:

OVRST 1

If you send the reset command without first removing the OV condition, the supply will fire the OV again.

NOTE

If the programmable OV fails, the supply has a fixed OV circuit which will fire the SCR crowbar if the

 

voltage exceeds 120% of the maximum rated output. The fixed OV circuit will also fire the SCR

 

crowbar if the supply is off (line cord disconnected) and an external source is supplying voltage which

 

exceeds 120% of the maximum rated output.

Overcurrent Protection (OCP)

The OCP is a protection feature employed by the power supply to guard against excessive output currents. When the output enters the + CC mode and the OCP is enabled, the OCP circuit down programs the output voltage and disables the output.

To enable the OCP, for output channel 1, send the command

OCP 1,1

To disable the OCP, send the command

OCP 1,0

You can find out the OCP setting by sending the following query and addressing the power supply to talk.

OCP? 1

The response from the power supply is either a "0" to indicate that OCP is off or a ''1" to indicate that it is on. To reset the output channel after an overcurrent trip, you can either disable the OCP and send the reset command, or you can reduce the output current below the programmed current and then send the reset command. To reset output 1, send the command:

OCRST 1

NOTE

The supply can report a fault condition when an output is in overvoltage or overcurrent. Although the

 

OVRST and OCRST commands reenable the output, they do not clear the fault register. As a

 

housekeeping measure, it is advisable to always clear the fault register by querying its value after an OV

 

or OC reset.

Multiple Output Storage & Recall

The power supply has 10 internal registers each of which can store the voltage and current settings of all the outputs. By storing voltage and current settings for all outputs and recalling them later, you can have significant savings in programming time. (See Supplemental Characteristics in Table 1-1).

72 Remote Operation