
Manual
ibaBM-PN
62
Issue 1.9
9.4
Calculation of the telegram size with 32Mbit Flex
The data size per participant is dynamically allocated in a 32Mbit Flex ring. The data size
is calculated by ibaPDA and it depends on the configured number of analog and digital
signals and the smallest configured timebase in the ring.
In ibaPDA, in the link view of the ibaFOB-D card on the “Configuration“ tab, you can
access a simulator. This simulator calculates the data amount which can be transferred
via the FO connection with the 32Mbit Flex protocol.
Figure 43: Simulation of the bandwidth distribution in a 32Mbit Flex telegram
The data sizes in bytes of each device on the link and the timebase of the data acquisi-
tion on the link (in µs) is needed for the calculation.
The values can be manually entered or taken automatically from the current configura-
tion, either with a click on the button <Estimate values from current configuration> or
when the respective link of the ibaFOB card is marked in the module tree.
The devices in the Flex ring and the corresponding data sizes are listed in the grid on
the left. Address 0 corresponds to the Ethernet channel and is not editable.
The section “Flex frame utilization” indicates how much of the bandwidth is still availa-
ble. The color of the section changes with the utilization rate:
Green: OK
Orange: bandwidth for the Ethernet channel < 3 kB/s
Red: too much data.
The automatically derived values are a first estimation: The firmware of the individual
devices determines where in the Flex telegram the data are transferred. Filling bytes can
be inserted between the requested data. After the configuration has been applied with a
click on <OK> or <Apply>, the actual data values are displayed on the “Info“ tab.