Beckhoff EL3681 Documentation page 60

Commissioning
Fig. 42: Selecting BOOL-type PDO
According to the default setting, only certain PDO objects are now available for selection. In this example,
the input of channel 4 of the EL1004 terminal is selected for linking. In contrast, the checkbox "All types"
must be ticked to create the link for the output variables, in order to allocate a set of eight separate output
bits to a byte variable in this case. The following diagram shows the whole process:
Fig. 43: Selecting several PDOs simultaneously: activate "Continuous" and "All types"
Note that the "Continuous" checkbox was also activated. This is designed to allocate the bits contained in the
byte of the "nEL2008_value" variable sequentially to all eight selected output bits of the EL2008 Terminal. It
is thus possible to subsequently address all eight outputs of the terminal in the program with a byte
corresponding to bit 0 for channel 1 to bit 7 for channel 8 of the PLC. A special symbol ( ) on the yellow or
red object of the variable indicates that a link exists. The links can also be checked by selecting "Goto Link
Variable" from the context menu of a variable. The opposite linked object, in this case the PDO, is
automatically selected:
60 Version: 3.0 EL3681