BECKHOFF FM33xx - Manual (Page 28)

I/O configuration
FM33xx 23
Reaction on I/O-fault
Channel settings for the TC-Plug modules
The number of active analog channels can be configured by means of the
channel settings. Only the data of the channels that are associated are
transmitted over the fieldbus and can be evaluated. At least one channel
must be associated in the minimal configuration. A maximum of 32
channels can be associated through the configuration. If a channel is to be
associated, the user can choose between complex or compact mapping of
the channel data. Only compact mapping is presently supported. This
means that 16 data bits are transmitted over the fieldbus for each channel.
Configuring the channels
At least one channel must be configured in the minimal configuration. This
means that a compact association must be configured for at least one
channel.