ibaBM-DP
Manual
Issue 1.7
91
Note
The status of the PROFIBUS system and thus the events, are generated by numerous
asynchronous monitorings of various PROFIBUS telegrams in ibaBM-DP.
Thus, the correct time sequence of the reported events cannot be guaranteed. Events,
that have been generated within a short continuous time period, always have to be an-
alyzed in common.
10.4.3 Display of bus voltages in the I/O Manager
ibaBM-DP has a transducer (8 Bit, sampling rate 10 ns). With this transducer, you can
measure the bus voltages. The measured voltages are displayed as bar diagram in the
I/O Manager. Moreover, you can acquire the bus voltages as signals. For this purpose,
use the “Slave diagnostics” module (see chapter 10.3.6 and 10.4.4).
Measurement principle
Fig. 60: Measurement principle for determining the bus voltages
For determining the voltage difference between High and Low level, one voltage value
will be determined in the High and Low status each. The difference is the measured value
for the level height.
The measurement in the High status is done in situations, where the level is at High for
at least two consecutive bits after the level has changed from Low to High. The values
are measured at the end of the first bit. Thus, a nearly steady state of the level at the
time of the measurement can be assumed.
