
ibaBM-PN
Manual
Issue 1.9
23
The following data types are supported: BYTE, WORD, DWORD, INT, DINT, FLOAT and
DOUBLE in Big/Little Endian format. These data amounts represent the limit values for
the overall data amount on a Flex ring that can be transferred via an FO link.
8.9.2
Ring topology
Figure 12: Data acquisition in the 32Mbit Flex ring
In a ring with 32Mbit Flex protocol, up to 15 devices can be connected. In the ring, all
configuration and process data are transmitted.
ibaPDA automatically detects the devices in the ring and automatically determines the
maximum possible sampling rate, depending on the type and number of the devices.
In the ring, also other 32Mbit Flex capable iba devices can be integrated, e. g. ibaPADU-
S-CM like in the example above. The devices in the ring are addressed using the rotary
switch for the device address (rotary switch S2 for ibaBM-PN).
The individual device in the cascade can work with different access cycles. However,
these cycles have to be an integer multiple of the smallest cycle; e.g: device #1 works
with 0.5 ms, device #2 with 1 ms, device #3 with 4 ms, etc. If the max. data rate is ex-
ceeded, ibaPDA issues an error message that advices you to enhance the timebase and
decrease the data amount.
The calculation of the maximum data amount is based on the fastest device in the ring.
i.e. an increase in the cycle time of slow devices in the ring does not lead to an increased
data transfer. Only when the cycle time of the fastest device in ring is increased, the data
amount can be increased.
For further information about the distribution of the data amount in the Flex ring,
please see chapter 9.3.
Note
Due to the large data amounts which are usually acquired with ibaBM-PN, it is in most
cases appropriate only to operate one device on a 32Mbit Flex link (see chapter 8.1).