NSK EDD Megatorque Motor, User Manual

Page: 337 / 398

10. Maintenance
— 10-5 —

EEPROM

The Driver Unit Model EDD has an EEPROM for the data backup. The limitation on the number of times
for writing and deleting is approximately 100 000.

The alarm E2 (ROM error) occurs when the EEPROM reaches its life.

The EEPROM does not require any battery for data backup.

We do not replace the EEPROM itself. The Driver Unit must be replaced when the life of the EEPROM
has come to end.

The EEPROM backs up the settings at the events described in “Table 10-6: Timing for writing data to the
EEPROM.”

When setting the same data repeatedly, it is not necessary to change the data, thus actual data
backup won’t be performed.

When the master controller frequently changes parameters in the middle of operation, we
recommend setting the parameter WM1 (Prohibit to back up data). However, if you require
backing up the settings, execute the command WD (Write data) before turning the power off.
It requires approximately 40 seconds for the backup. Do not turn off the power in the middle of
backing up the data.
Table 10-6: Timing for writing data to the EEPROM
Event Object of backup
Way to prohibit the data
backup
At the end of life of the EEPROM
Turning on the control
power Number of times for
power on
None
• Readouts of the command TA/HI (Read out
alarm history) may not be correct.
• All the other parts will operate normally.
Occurrence of an alarm
Occurrence history
of an alarm
Setting of the home
position
Setting history
Parameter AO
(Absolute position
scale offset) The EEPROM cannot correctly back up the
parameter AO, and thus the alarm E2 (ROM
error) occurs.
• Setting of parameter
• Editing program
• Setting of function to
the ports of input and
output.
Setting data
Set the parameter WM
(Write mode to EEPROM) to
WM1 (Prohibit data backup)
All settings won’t be correctly backed up, and
consequently the alarm E” (ROM error) occurs.

When replacing the Driver Unit

Because the standard Driver Units Model EDD are interchangeable each other, simply replace with the
new Driver Unit that has the same reference number, then reset the all settings of parameters and
programs.

In case of a special Driver Unit, please refer to the specification documents for
interchangeability.