Appendix; Precautions For Setting Operation; Precautions When Setting Via Cc-Link Communication/Modbus Communication - Mitsubishi Electric MDU-BN Instruction Manual

8. Appendix

8.1 Precautions for setting operation

The display can be used to set and clear the items described in " 7.1.2 Method for various settings, " " 7.1.3 Method for resetting alarms, " and " 7.1.4 Method
for resetting fault cause/current, maximum value, electric energy, and reactive energy. "
When items are set or cleared, the non-volatile memory storage will be overwritten for all of these except for the items described in " 7.1.2-4 Setting
method for day and time. "
It takes some time to overwrite the non-volatile memory storage, and items may not be properly overwritten in the non-volatile memory if they are set or
cleared in quick succession. Therefore, as shown in the examples below, wait around three seconds after setting or clearing an item, before setting or
clearing another item (regardless of whether the items are similar or different).
<Consecutive setting example 1> Consecutive setting of different settings (demand time limit, alarm reset method, storage clear)
Demand time limit
Wait
setting
<Consecutive setting example 2> Consecutive setting of different settings (demand time limit, storage clear)
Demand time limit
Wait
setting

8.2 Precautions when setting via CC-Link communication/MODBUS communication

If using a product with CC-Link communication/MODBUS communication, CC-Link communication can also be used to send certain commands and
setting values to a MDU, allowing items to be set and cleared just as when operating the display (as described above).
(Refer to " MDU Breaker Programming Manual " for details on what can be configured and cleared.)
The non-volatile memory storage is overwritten (depending on what is set or cleared) when setting and clearing over CC-Link communication
/MODBUS communication, and items may not be properly overwritten in the non-volatile memory if set/clear commands are transmitted in quick
succession. Therefore, as shown in the examples below, wait around three seconds after transmitting a set or clear command, before transmitting
another command (regardless of whether the commands are similar or different).
<Consecutive transmission example 1> Consecutive transmission of different commands (demand time limit, alarm reset method, storage clear)
Send demand time
limit setting &
Wait
receive
normal response
<Consecutive transmission example 2> Consecutive transmission of different commands (demand time limit, storage clear)
Send demand time
limit setting &
Wait
receive
normal response
Clear all
3 s
Clear electric
energy
3 s
Send clear all &
receive normal
3 s
response
Send clear fault
current/cause
& receive
3 s
normal response
Wait Alarm reset method
3 s setting
Demand time limit
Wait
setting
3 s
Send alarm reset
method setting &
Wait
receive
3 s
normal response
Send demand time
limit setting &
Wait
receive
3 s
normal response
58
Wait Demand time limit
setting
3 s
Clear fault
Wait
current/cause
3 s
Send demand time
limit setting &
Wait
receive
3 s
normal response
Send clear electric
Wait
enegy & receive
3 s
normal response
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