Diagnostic LEDs
The Bus Coupler has two groups of LEDs for the display of status. The "DIAG LEDs" on the left indicate the fieldbus, PLC and K-Bus state. Two green LEDs (Power LEDs) are located in the top right corner of the Bus Coupler. They are used for displaying the supply voltage of the BX Controller and the 24 VDC supply of the power contacts.
LEDs for power supply diagnostics
LED (Power LEDs) |
Meaning |
---|---|
Left LED off |
Bus Coupler has no voltage 24 VDC |
Right LED off |
No power supply 24 VDC connected at the power contacts |

The DIAG LEDs are sub-divided as follows:
- Bus: fieldbus diagnostics
- PLC: PLC diagnostics
- I/O: K-bus diagnostics
The LEDs can be off, green, orange or red.

After switching on, the Bus Coupler immediately checks the connected configuration. The I/O LED goes out if the start-up was successful. A red I/O LED indicates a Bus Terminal error. The error type is shown in the display. This permits rapid rectification of the error.
LED bus - fieldbus diagnostics
No meaning in the case of the BX8000, since no fieldbus interface exists. The LED can be operated from the PLC by ADS.
LED PLC - PLC diagnostics
LED |
Meaning |
---|---|
LED off |
PLC stop or no program available |
LED red |
Flashing - the set task time is exceeded from time to time |
LED orange |
PLC running without boot project (only during the on cycle), LED flashes orange during creating of the boot project |
LED green |
Boot project - PLC running (only during the on cycle) |
LED I/O - K-Bus diagnostics
LED |
Meaning |
---|---|
LED off |
No data are exchanged via the K-bus |
LED red |
error flashing - error type - display |
LED orange |
Register or KS2000 online access |
LED green |
K-bus OK and running |
Error code for K-bus diagnostics
Error |
Error |
Description |
Remedy |
---|---|---|---|
0 |
- |
EMC problems |
|
1 |
0 |
EEPROM checksum error |
Enter factory settings with the KS2000 configuration software |
1 |
Code buffer overflow |
Insert fewer Bus Terminals. Too many entries in the table for the programmed configuration | |
2 |
Unknown data type |
Software update required for the Bus Coupler | |
2 |
- |
Reserve |
- |
3 |
0 |
K-bus command error |
|
4 |
0 |
K-bus data error, break behind the Bus Coupler |
Check whether the n+1 Bus Terminal is correctly connected; replace if necessary. |
n |
Break behind Bus Terminal n |
Check whether the KL9010 Bus End Terminal is connected | |
5 |
n |
K-bus error in register communication with Bus Terminal n |
Exchange the nth Bus Terminal |
6 |
0 |
Error at initialization |
Exchange Bus Coupler |
1 |
Internal data error |
Perform a hardware reset on the Bus Coupler (switch off and on again) | |
2 |
DIP switch changed after a software reset |
Perform a hardware reset on the Bus Coupler (switch off and on again) | |
7 |
0 |
Note: cycle time was exceeded |
Warning: the set cycle time was exceeded. This indication (flashing LEDs) can only be cleared by booting the Bus Coupler again. |
9 |
0 |
Checksum error in Flash program |
Transmit program to the BX again |
1 |
Incorrect or faulty library implemented |
Remove the faulty library | |
10 |
n |
Bus Terminal n is not consistent with the configuration that existed when the boot project was created |
Check the nth Bus Terminal. The boot project must be deleted if the insertion of an nth Bus Terminal is intentional. |
14 |
n |
nth Bus Terminal has the wrong format |
Start the Bus Coupler again, and if the error occurs again then exchange the Bus Terminal |
15 |
n |
Number of Bus Terminals is no longer correct |
Start the Bus Coupler again. If the error occurs again, restore the manufacturers setting using the KS2000 configuration software |
16 |
n |
Length of the K-bus data is no longer correct |
Start the Bus Coupler again. If the error occurs again, restore the manufacturers setting using the KS2000 configuration software |