ADS diagnostics

Status inputs

It is possible to monitor the BK/BC9000, B/C900 Bus Coupler's communication in the system manager. Each Bus Coupler has status inputs that can be found in the hardware tree.

ADS diagnostics 1:
Status inputs of the BC9000

Coupler state

Value

Meaning

0x0000

No error

0x0001

Bus Terminal error; there is a K-bus error

0x0002

Configuration error; the parameterized configuration does not match the actual configuration

MissedCnt

Ideal configuration:
The task time is always longer than the Ethernet transmission time. An Ethernet telegram is transmitted at the beginning of the task, and it returns it to the PC again after a period of time, tEth. If the time tEth is always smaller than the task time that has been set, the value in the MissedCnt counter remains constant.

ADS diagnostics 2:
Task time longer than Ethernet propagation delay

If, after the task time has elapsed, an Ethernet telegram has still not arrived at the PC, only reaching it after the next task has started, then TwinCAT will continue to work with the old input data. In addition, the MissedCnt counter is incremented.

ADS diagnostics 3:
Task time shorter than Ethernet propagation delay

This can have the following causes:

The two following diagnostic inputs have different meanings, depending on the transmission type.

TCP/IP diagnosis

BoxState

Value

Meaning

0x0000

No error

0x0001

No current inputs

MissedCnt

Value

Meaning

0xyyyy

Number of telegrams that have not returned in time for the start of the task. This value should remain almost constant. If the value keeps rising, the task time should be lengthened.

UDP/IP diagnosis

BoxState

Value

Meaning

0x0000

No error

0x0001

No current inputs

0x0002

Outputs are written as zero

0xxxzz

xx - warning level. The value here is incremented by one each time the data is not received in time. When data is exchanged correctly, the value is decremented by one. When the maximum warning level (default value 100) is reached, zero is written to the output data, and it is only enabled again for the normal process image when the warning level has reached zero.

MissedCnt

Value

Meaning

0xyyyy

Number of telegrams that have not returned in time for the start of the task. This value should remain almost constant. If the value keeps rising, the task time should be lengthened.