Ethernet LED Indicators
Original instructions
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Introduction
There are several LEDs available on the front panel of each Modicon M340 module or processor, enabling rapid diagnosis of the PLC status:
These LEDs provide information on:
BMX NOE 01x0 LEDs
The following diagram shows the diagnostic LEDs on the BMX NOE 01x0 modules. Note that two displays exist, depending on whether you are using firmware V1 or V2 (or greater) of the module.
The colors and blink patterns of the LEDs indicate the status and operating conditions of Ethernet communications on the module:
Label
Pattern
Indication
RUN (green): operational state
on
  • Module is operating and configured.
flashing
  • Module is blocked by a software detected error.
off
Module is not configured (application is absent, invalid, or incompatible).
ERR (red): detected error
on
Processor, system, or configuration detected error
flashing
  • Module is not configured (application is absent, invalid, or incompatible).
  • Module is blocked by a software detected error.
off
Normal (no detected errors)
ETH STS (green): Ethernet communication status
on
Communication OK
2 flashes
Invalid MAC address
3 flashes
Link not connected
4 flashes
Duplicate IP address
5 flashes
Waiting for a server IP address
6 flashes
Secure and safe mode (with default IP address)
7 flashes
Configuration conflict between rotary switches and internal configuration
CARDERR (red): memory card detected error
on
  • Memory card is missing.
  • Memory card is not usable (bad format, unrecognized type).
  • Memory card had been removed and reinserted.
off
  • Memory card is valid and recognized.
Note 1: Rapid flashing is defined as ON for 50 ms and OFF for 50 ms.
Note 2: Slow flashing is defined as ON for 200 ms and OFF for 200 ms.
BMX P34 2020, BMX P34 2030/20302 Processor LEDs
The following diagram shows the diagnostic LEDs on the BMX P34 2020 processor. Note that two displays exist, depending on whether you are using firmware V1 or V2 (or greater) of the processor.
The following diagram shows the diagnostic LEDs on the BMX P34 2030/20302 processor. Note that two displays exist, depending on whether you are using firmware V1 or V2 (or greater) of the processor.
The colors and blink patterns of the LEDs indicate the status and operating conditions of Ethernet communications on the module:
Label
Pattern
Indication
RUN (green): operational state
on
  • PLC hardware and PLC program operations are normal.
  • Module is in RUN state.
flashing
  • PLC is in STOP mode or a blocking error in the application has been detected.
  • Processor is configured but not in RUN state.
off
PLC is not configured (application is absent, invalid, or incompatible).
ERR (red): detected error
on
Processor, system, or configuration detected error
flashing
  • PLC is not configured (application is absent, invalid, or incompatible).
  • PLC is in STOP mode or a blocking error in the application has been detected.
off
Normal (no detected errors)
ETH STS (green): Ethernet communication status
on
Communication OK
2 flashes
Invalid MAC address
3 flashes
Link not connected
4 flashes
Duplicate IP address
5 flashes
Waiting for a server IP address
6 flashes
Secure and safe mode (with default IP address)
7 flashes
Configuration conflict between rotary switches and internal configuration
CARDERR (red): memory card detected error
on
  • Memory card is missing.
  • Memory card not usable (bad format, unrecognized type).
  • Memory card content is inconsistent with internal RAM application.
off
  • Memory card is valid and recognized.
  • Application on card is consistent with the internal RAM application.
I/O (red): input/output status
on
  • Error detected on a configured module or CPU channel
  • Configuration mismatch with the application (module missing...)
off
Normal (no detected errors)
SER COM (yellow): serial data status
flashing
Data exchange (send/receive) on the serial connection in progress
off
No data exchange on the serial connection
CAN RUN (green): CANopen operations
on
CANopen network operational
rapid flashing (note 1)
Automatic detection of data flow or LSS services in progress (alternates with CAN ERR).
slow flashing (note 2)
CANopen network is pre-operational.
1 flash
CANopen network is stopped.
3 flashes
Downloading CANopen firmware.
CAN ERR (red): CANopen detected error
on
CANopen bus is stopped.
rapid flashing (note 1)
Automatic detection of data flow or LSS services in progress (alternates with CAN RUN).
slow flashing (note 2)
CANopen configuration is not valid.
1 flash
At least one detected error counter has reached or exceeded alert level.
2 flashes
A guard event (NMT slave or NMT master) or a heartbeat event has occurred.
3 flashes
The SYNC message was not received before the end of the communication cycle period.
off
No error detected on CANopen.
CARDAC (green): memory card access
Note: This LED is located under the memory card door.
on
Access to the card is enabled.
flashing
Activity on the card: during each access, the card LED is set to OFF, then back to ON.
off
Access to the card is disabled. You can remove the card after you disable card access by setting system bit %S65 to 0.
Note 1: Rapid flashing is defined as ON for 50 ms and OFF for 50 ms.
Note 2: Slow flashing is defined as ON for 200 ms and OFF for 200 ms.
LED Differences Between Firmware V1 and V2 Modules for both BMX NOE 01x0 and BMX P34 20x0x
The following table describes the meaning of the ETH ACT and ETH 100 LEDs on the front panel for firmware V1 NOE and CPU modules.
Label
Pattern
Indication
ETH ACT (green): Ethernet communication (transmission/reception activity)
on
Ethernet link detected: no communications activity.
off
No Ethernet link detected.
flashing
Ethernet link detected: receiving or sending packets.
ETH 100 (green): Ethernet transmission speed
on
Ethernet transmission at 100 Mbit/s (Fast Ethernet).
off
Ethernet transmission at 10 Mbit/s (Ethernet) or no link detected.
The following table describes the meaning of the ETH ACT and ETH LNK LEDs on the front panel for firmware V2 NOE and CPU modules.
Label
Pattern
Indication
ETH ACT (green): Ethernet communication (transmission/reception) activity
on
Communications activity detected.
off
No communications activity detected.
ETH LNK (green): Ethernet link status
on
Ethernet link detected.
off
No Ethernet link detected.
NOTE:
  • Rapid flashing is defined as ON for 50 ms and OFF for 50 ms.
  • Slow flashing is defined as ON for 200 ms and OFF for 200 ms.