Agilent Technologies 6050A Protection Features, Status Reporting, Resetting Latched Protection

The SYST:ERR? query (or key) reads back the errors in the order in which they occurred (the error queue can hold up to 30 entries). Once the error is read back it is removed from the list. A value 0 indicates there is no error; and 0 will be

returned when all errors in the list have been read. Pressing the key displays just the error number. The SYST:ERR? query returns the error number and a short description of the error to the computer. Refer to Chapter 6 in the Agilent Electronic Loads Programming Reference Guide.

Local programming errors generated by front panel operations are not put into the error list, but are immediately put on the Electronic Load’s front panel display; e.g., ’OUT OF RANGE’.

Status Reporting

The Electronic Load incorporates a status reporting capability. Various status conditions within the Electronic Load can be reported using this capability. The user determines which condition(s) will be reported. Chapter 5 of the Agilent Electronic Loads Programming Reference Guide describes each of the status registers in the Electronic Load. (These registers, including the channel status registers, are all maintained in the mainframe.) Notice that the same information is available in both the channel status and questionable status registers, but the channel registers are organized by channel, and the questionable registers are organized by fault. Therefore, depending on which channels and/or faults are most critical in your application, you can use one branch to localize selected faults quickly, and use the other branch for broader fault reporting. By knowing that only a particular fault (questionable branch) or a particular channel (channel branch) is enabled to initiate a service request, you can eliminate the need to read one or more registers to locate a fault.

Protection Features

Each load module includes the following protection features:

∙Overvoltage

∙Overcurrent (hardware and software)

∙Overpower (hardware and software)

∙Overtemperature

∙Reverse Voltage

The appropriate bit(s) in the mainframe’s status registers are set when any of the above protection features are active. Also, the Prot annunciator comes on and the front-panel alphanumeric display indicates which condition(s) have been detected. For example, if an overtemperature (OT) condition has been detected causing a module’s input to be turned off (protection shutdown, PS), the display will indicate "PS OT".

Resetting Latched Protection

All of the protection features latch (remain set) when they are tripped, except for the hardware overcurrent and reverse voltage. The latched protection features can be reset via the GPIB (*RST or INP:PROT:CLE commands) or at the front

panel (key). Of course, the condition that caused the protection feature to trip must be removed or it will trip again as soon as it is reset.

To protect the Electronic Load from possible damage, the input voltage must not exceed the maximum input voltage rating specified in the module-specific pages supplied with each module. Never apply the ac line voltage to a module’s input binding posts.

28 Operation Overview