C.11 Changing Drive Parameters
This section describes how the drive handles parameter changes by MEMOBUS/Modbus.
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Drive Operations on Parameter Change
When drive parameters are changed by MEMOBUS/Modbus communication, the drive performs the following operations:
• The upper/lower limit of the parameter changed is checked. If the new value is out of range, the old value remains active.
• Parameter settings are refreshed in the RAM, i.e., the parameter change is activated immediately.
• The default settings of related parameters are changed.
• If multiple registers are written and only one data is invalid, all data sent are discarded.
If no Enter command is sent, parameter changes will be lost if the power is switched off.
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Issuing an Enter Command
If parameters are changed from a PLC using MEMOBUS/Modbus communication the values are changed in the drive RAM
only. When the power is turned off all changes will be lost. An Enter command can be sent to save changes in the EEPROM
(non-volatile memory) and thereby prevent the loss of parameter settings. In order to perform an Enter command "0" must be
written in register number 900H. This register is "write only".
Table C.6 Enter Command
Register No. Description
0900H Writes data into the EEPROM (non-volatile memory). Parameter changes remain even if the power supply is cycled.
Note: 1. Because the EEPROM can be written to a maximum of 100,000 times, refrain from writing to the EEPROM too often. The Enter
command
registers are write-only. Consequently, if these registers are read, then the register address will be invalid (Error code: 02H).
An Enter command is not required if reference or broadcast data are sent to the drive.
2. Parameter data cannot be written to EEPROM during undervoltage, even using 0900H.
3. If undervoltage occurs when a making several parameter changes issued with a single ENTER command, the writing process may be
aborted before all of the new changes have been written. Because all of the data has not yet been written, the EEPROM data error
“CPF06” will be displayed the next time power to the drive is cycled. To prevent this problem, wait approximately 5 seconds after
issuing the ENTER command before shutting off drive power.
C.11 Changing Drive Parameters
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YASKAWA ELECTRIC SIEP C710606 31B YASKAWA AC Drive – J1000 Technical Manual
http://nicontrols.com
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