LED Status Display¶
The LEDs are located at the front of module. There are 4 different groups:
- 5 system LEDs (PWR, STA1 ETH, STA2 ETH, S-ERR and I/O-Bus) show the operation status of the module and display possible errors.
 - 4 Ethernet status LEDs located at the Terminal Unit TU520-ETH
 - 11 status LEDs for the Serial Interfaces an the CANopenâ Interface
 - 1 LED to display the presence of the process supply voltage UP
 
| LED | Color | OFF | ON | Flashing | 
|---|---|---|---|---|
| PWR/RUN | green | Process supply voltage missing | Internal supply voltage OK, module ready for communication with IO Controller | Start-up / preparing communication | 
| yellow | — | — | — | |
STA1 ETH (System-LED “BF”)  | 
green | — | Device configured, cyclic data exchange running | — | 
| red | — | — | Device is not configured | |
| STA2 ETH (System-LED “SF”) | green | — | — | Got identification request from IO Controller | 
| red | No system error | System error (collective error) | — | |
| S-ERR | red | No error | Internal error | – | 
| I/O-Bus | green | No expansion modules connected or communication error | Expansion modules connected and operational | — | 
| LED | Color | OFF | ON | Flashing | 
|---|---|---|---|---|
| ETH1-Link | green | No connection at Ethernet interface | Connected to Ethernet interface | — | 
| ETH1-Rx Tx | yellow | — | Device is transmitting telegrams | Device is transmitting telegrams | 
| ETH2-Link | green | No connection at Ethernet interface | Connected to Ethernet interface | — | 
| Eth2-Rx Tx | yellow | — | Device is transmitting telegrams | Device is transmitting telegrams | 
| LED | Color | OFF | ON | Flashing | 
|---|---|---|---|---|
| COMx TxD | yellow | No data transmission over serial network | – | Channel is transmitting data via the serial interface (flashing rate depending on the telegram transmission frequency) | 
| COMx RxD | yellow | No data reception from serial network | – | Channel is receiving data from the serial interface (flashing rate depending on the telegram reception frequency) | 
| COMx STA | yellow | RS-232: RTS signal not active RS-485: Channel is in reception mode RS-422:Channel is not enabled  | 
RS-232: RTS signal is active RS-485: Channel is transmitting RS-422: Channel is enabled (able to receive and transmit)  | 
– | 
| COMx-ERR | red | Channel enabled, no error OR Channel deactivated  | 
Channel boot up | Channel error (receive buffer overflow) | 
| LED | Color | OFF | ON | Flashing | 
|---|---|---|---|---|
| CAN-RUN | yellow | – | Device configured, CANopenâ Bus in OPERATIONAL state and cyclic data exchange running | Flashing Cyclically: CANopenâ Bus in PRE-OPERATIONAL state and slave is being configured Single flash: CANopenâ Bus in STOPPED state.  | 
| CAN-STA | yellow | No data transmission | Channel is transmitting data | – | 
| CAN-ERR | red | No error | CANopenâ bus is OFF | Flashing Cyclically: Configuration error Single flash: Error counter overflow due to too many error frames Double flash: A Node-Guard or a Heartbeat event occurred  | 
| LED | Color | OFF | ON | Flashing | 
|---|---|---|---|---|
| UP | green | No process voltage available | Process voltage available | – |