Manual
ibaBM-DP
92
Issue 1.7
The measurement in the Low status is done according to the same principle, i.e. in situ-
ations where the level is at Low for at least two consecutive bits after the level has
changed from High to Low.
With an increasing transfer rate, the number of available measurement values decreases
as the time period of one bit is getting shorter and shorter. Moreover, the time of meas-
urement within one bit has a Jitter. With an increasing transfer rate, this Jitter becomes
more and more relevant as the voltage does not reach a steady state anymore. Thus,
the precision of the measurement gets lower at high transfer rates.
The measurement is only done for status telegrams which are exchanged between mas-
ter and slaves. Depending on the bus cycle (depending on the transfer rate and the
number of participants), the update rate of the bus voltages can be in the seconds range.
The ibaBM-DP hardware does not allow for a more frequent measurement. The focus of
the voltage measurement in the ibaBM-DP lies on the statistic evaluation of the voltage
ratio on the bus and the long-term acquisition of the voltages. The measurement of the
bus voltages in ibaBM-DP is not suited for acquiring and analyzing fast processes on the
bus voltage.
Bar diagram
When selecting the bus node “X40: Bus0” or “X41: Bus1” of an ibaBM-DP in the I/O
Manager, you can see the bar diagram of the bus voltages.
Fig. 61: Bar diagram of the bus voltages
