Checksum Errors; Runtime Error Messages - Agilent Technologies 6641A Operating Manual

Error Display
No.
El FP RAM
E2 FP ROM
E3 EE CHKSUM
E4
PRI XRAM
E5 PRI IRAM
E6 PRI ROM
E7 GPIB

Checksum Errors.

If the display shows EE CHKSUM, the power supply has detected an EEPROM checksum error. A checksum error can
occur due to the following conditions:
Excessive number of write cycles to an EEPROM (see "Nonvolatile Memory Write Cycles" in "Supplemental
I
Characteristics" tables). This condition, which would appear only after extended use, is not recoverable and requires
service.
Loss of ac input power during a checksum calculation. This condition, which is very unlikely, is recoverable.
I
You may be able to recover from a checksum error by writing to the EEPROM while the power supply is in the calibration
mode. To do this, proceed as follows:
1. Enable the calibration mode by pressing
2. PASWD will appear on the display.
3. Press the number keys corresponding to the password, followed by
Note
On new equipment, the calibration password corresponds to the four-digit model number (such as
4. Save any operating state (for example, press
5. Turn the power off and then back on.
A normal display free of error messages should appear. If not, the power supply requires service.

Runtime Error Messages

Under unusual operating conditions, the VOLT or AMPS display may show +OL or -OL. This indicates that the output
voltage or current is beyond the range of the meter readback circuit. Table 3-4 shows other error messages that may appear
at runtime.
Display
EE WRITE ERR EEPROM status timeout
SBUB FULL Message too long for buffer
SERIAL DOWN Failed communication with
front panel
STK OVERFLOW Front panel stack overflow
58 Turn-On Checkout
Table 3-3. Power-On Selftest Errors
Failed Test
Front Panel RAM
Front Panel ROM checksum
EEPROM
Primary external RAM
Primary internal RAM
Primary ROM checksum
GPIB R/W to serial poll
). See "Appendix A - Calibration" for more information about the calibration password.
Table 3-4. Runtime Errors
Meaning
Error Display
No.
E8 SEC RAM
E9 SEC ROM
E10 SEC 5V
Ell
TEMP
E12 DACS
.
. The Cal annunciator will go on.
).
Display
UART FRAMING UART byte framing error
UART OVERRUN Overfilled UART receive buffer
UART PARITY UART byte parity error panel
Failed Test
Secondary RAM
Secondary ROM checksum
Secondary 5 V ADC reading
Secondary ambient
thermistor reading
Secondary VDAC/IDAC
readback
Meaning