Problems and Countermeasures

Master Unit LED Error Description [Reference]
MS NS
Green Light ON Green Light ON Normal communication Normal condition
Green Light ON Green Light Blinking During connection establishment Processing connection establishment.

(The green NS LED will be ON in a few seconds.)

Master function in stop state.

(When communication does not start, master analysis with NetMeter is required.)

Green Light ON Red Light Blinking Communication error

See also: Master: Communication Error

Slave disconnected from the network (Remote I/O communication error)

Slave not added to the network (Scan list collation error)

Communications power supply OFF (Error detection after the communication establishment)

Green Light ON Red Light ON Busoff detection

Duplicate MAC ID

See also: Master: Busoff Detection

Busoff detection Communication stopped due to critical error.

Duplicate MAC ID The MAC ID configuration was duplicated.

(This error occurs only during unit start-up)

Green Light ON Light OFF Unestablished communication

See also: Master Communication Unestablished

No slave (Error detection before communication establishment)

Communications power supply OFF (Error detection before the communication establishment)

Duplicate MAC ID The MAC ID configuration was duplicated.

Red Light Blinking - Configuration error Master unit configuration error

Refer to the respective device manuals.

When Epson RC+ was configured as a master:

See also: Master: Configuration Error

Slave disconnected from the network (Remote I/O communication error)

Slave not added to the network (Scan list collation error)

Duplicate MAC ID The MAC ID configuration was duplicated.

Red Light ON - Module error Broken master unit → Unit Replacement
Light OFF Green Light Blinking Absent slave

See also: Absent Slave

No slave (Error detection before communication establishment)

Communications power supply OFF

Light OFF Light OFF Network

Absent slave

See also: Uninitialized Network

Master unit start-up error

No slave (Error detection before communication establishment)

Communications power supply OFF

Process Flowchart

* See also:

Symbol See also:
1 Examining a Problem
2 Slave: Not Operating
3 Slave Communication Error Detection / Busoff Detection / Not-added
4 Master: Busoff Detection
5 Master Communication Unestablished
6 Master: Configuration Error
7 Absent Slave
8 Uninitialized Network