CM572-DP PROFIBUS DP Communication Module Bus Diagnosis

Master Main State displays the current State of the PROFIBUS® DP Master.

Display	Meaning
Operate	The PROFIBUS® DP Master is in data exchange. In a data exchange the inputs of the PROFIBUS® DP Slaves are read and the output information is transferred to all DP Slaves.
Clear	The PROFIBUS® DP Master reads the input information of the PROFIBUS® DP Slaves and holds the outputs of the PROFIBUS® DP Slaves in a safe condition.
Stop	The PROFIBUS® DP Master is in the state Stop that means no data exchange takes place between the PROFIBUS® DP Master and the PROFIBUS DP Slaves. The Master was stopped by the application program or it had to go in the state Stop because of a bus error.
Offline	The PROFIBUS® DP Master does not exist on the bus, it is not online. This can happen if no or faulty bus parameters are set for the PROFIBUS® DP Master. Furthermore this can happen if the correct bus parameters are set, but the application program has not activated the PROFIBUS® DP Master for data exchange on the bus.

Master Status shows individual bus errors. A pending error is displayed by a red LED. The meaning of the individual errors is described in the following:

Master Status	Meaning
Timeout	The device has detected a skipped Timeout supervision time because of rejected PROFIBUS® telegrams. It is an indication for bus short circuits while the PROFIBUS® DP Master interrupts the communication. The number of detected timeouts is fixed in the field Bus Monitoring. The bit will be set when the first timeout was detected and can only be deleted via a reset of the device.
Not ready	Host Not ready shows that the application program has not started or it has stopped the PROFIBUS® DP Master.
Auto Clear	The Auto Clear Error displays that device has stopped the communication to all Slaves and it has reached the auto-clear end state.
Slave Error	The Slave Error shows that at least 1 Slave is not in the cyclic data exchange with the PROFIBUS® DP Master.
Fatal Error	A Fatal Error has occurred. Because of a heavy bus error no further bus communication is possible.
Control Error	The Control Error displays that a parameterization error has occurred.

Bus Monitoring	Meaning
Event	The Event error shows that the device has detected bus short circuits. The number of detected events is fixed in the next row Short Circuit Counter. The bit will be set when the first event was detected and will not be deleted any more. This result and the counters are only set back by a reset of the DP Master.
Short Circuit Counter	The Short Circuit Counter counts the short circuit on the PROFIBUS® which were detected by the Master. Range of Value: 0 .. 65535 (rollover possible)
Transmissions Rejected Count	The Transmissions Rejected Count displays the number of rejected telegrams. A possible reason for this is that the PROFIBUS® DP Master itself can not receive the token anymore. Range of Value: 0 .. 65535 (rollover possible)