
Manual
ibaBM-PN
22
Issue 1.9
The installation location within the PROFINET line is
not
relevant. The PROFINET to-
pology can have a linear or a star structure.
Data acquisition via TAP / Sniffing is not possible in redundant networks, since the data
that can be acquired depends on the installation location.
Other documentation
SIEMENS FAQ on the basics of PROFINET system redundancy
What are the PROFINET redundancy functions?
https://support.industry.siemens.com/cs/ww/en/view/109756450
8.9
32Mbit Flex protocol and ibaFOB-D network
The ibaNet 32Mbit Flex protocol (referred to as "Flex protocol") is a manufacturer-specific
data transfer protocol by iba AG. This protocol serves to transfer measurement and con-
figuration data via FO connections between different iba devices. The PC cards of the
ibaFOB-D/ibaFOB-Dexp and ibaFOB-io-ExpressCard series as well as some devices for
data acquisition support this protocol.
8.9.1
Data amount and sampling rate
The Flex protocol works with a data transfer rate of 32 Mbit/s and supports up to 15
"Flex-capable" devices connected in a ring topology.
With 32Mbit Flex, the data amount and the sampling rate can be flexibly customized. The
data amount transferred per cycle depends on the sampling rate. Generally, the following
applies: The less data are transferred, the higher is the possible sampling rate.
For the signals to be measured, sampling rates of 500 Hz to 100 kHz can be realized,
which correspond to a timebase from 10 µs up to 2 ms. The maximum sampling rate also
depends on the acquisition device and can be found in the device manual. In ibaPDA
you can select even smaller sampling rates down to 1 Hz. This corresponds to a time-
base of 1000 ms. In this case, the timebase in the Flex ring is set to 2 ms and in ibaPDA
a subsampling is carried out. Redundant data is discarded by ibaPDA.
With 32Mbit Flex, up to 4060 bytes per cycle can be acquired and recorded depending
on the sampling rate.
For the max. possible data amount of 4060 bytes, the cycle time (timebase) is up to
1.4 ms. In the following table, you find reference values for the relation between cycle
time and the max. transferable data amount per cycle.
Timebase
Max data amount
1.4 ms
4060 bytes
1.0 ms
3100 bytes
0.5 ms
1540 bytes
0.025 ms
64 bytes
To acquire further samples, especially if several devices are connected in a Flex ring
topology, iba recommends using the simulator integrated in ibaPDA, see chapter 9.3.