Operating instructions

Status Reporting

Table 5-2. Questionable Status Bit Description

Mnemonic Bit

Value Meaning

VE/VF 0 1 Voltage Error (Voltage Fault)

CE/OC 1 2 Current Error (Overcurrent)

PE/OP 3 8 Power Error (Overpower)

TE/OT 4 16 Temperature Error (Overtemperature)

EPU 9 512 Extended Power Unavailable

UNR 10 l024 Unregulated input

RV 11 2048 Reverse Voltage on input

OV 12 4096 Overvoltage

PS 13 8192 Protection Shutdown

Bits 2, 5-8, 14, and 15 are not used

Output Queue

The Output Queue is a data structure that stores output messages until they are read from the electronic load. The Output

Queue stores messages sequentially on a FIFO (first-in, first-out) basis. When there is data in the queue, it sets Bit 4

(MAV bit) in the Status Byte register.

Standard Event Status

The function of the Standard Event Status register is standard on all IEEE 488.2 devices. Table 5-3 describes the standard

events that apply to the electronic load. Note that all programming errors that have occurred will set one or more of the

error bits in the Standard Event Status register. Programming errors are listed in Table 4-2.

The Standard Event Status register represents all of the standard events that have occurred since the last time this register

was read. Reading the Standard Event Status register resets it to zero.

The Standard Event Enable register can be programmed to specify which standard event bits are logically-ORed to

become Bit 5 (ESB bit) in the Status Byte register.

Note The present settings of the Standard Event Enable register can be saved in non-volatile memory if *PSC

is programmed to zero. The next time the unit is turned on, the Standard Event Enable register will be

programmed according to the saved settings.

Table 5-3. Standard Event Status Bit Description

Mnemonic Bit

Value Meaning

OPC 0 1 Operation Complete. The electronic load has completed all pending operations.

Programming *OPC causes this bit to be set when the electronic load completes

all pending operations

QYE 2 Query Error. The output queue was read when no data was present or the data in

the queue was lost. Errors in the range of -499 thru -400 can set this bit.

DDE 3 8 Device Dependent Error. Memory was lost, or self-test failed. Errors in the

range of -399 thru -300 can set this bit.

EXE 4 16 Execution Error. A command parameter was outside the legal range or

inconsistent with the electronic load’s operation, or the command could not be

executed due to some operating condition. Errors in the range of -299 thru -200

can set this bit.