Mitsubishi Electric MELSEC-L SERIES Basic User Manual page 248

*1 Devices on an Ethernet network contain the IP to Mac address mapping, called an "ARP cache". If a device on a line is
replaced by another device with the same IP address, the MAC address contained in the "ARP cache" and the MAC
address of the replaced device do not match; therefore, communications may not be performed normally. The "ARP
cache" is updated when the device is reset or after a certain period of time. The time varies depending on the devices.
*2 If the communication data code setting is different between the E71 and the connected device, error codes that are not
found in the error code list may be returned to the connected device. When receiving data with different data codes, the
E71 cannot decode commands normally. The E71 returns an error response according to the communication data code
setting.
( Page 137, Section 12.6.2 (1) (e), Remark)
*3 If the LG and FG terminals of the power supply module on the E71-connected station are not connected, the
communication line may be closed (disconnected) due to noise; therefore, communications with the connected device
may not be performed.
If the action above does not solve the problem, check for an error in each communication process and take corrective
action.
( Page 248, Section 16.6.4 to Page 257, Section 16.6.14)
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