Beckhoff EL34 Series Documentation page 73

Commissioning
Fig. 56: Selecting PDO of type BOOL
According to the default setting, certain PDO objects are now available for selection. In this sample the input
of channel 4 of the EL1004 terminal is selected for linking. In contrast, the checkbox "All types" must be
ticked for creating the link for the output variables, in order to allocate a set of eight separate output bits to a
byte variable. The following diagram shows the whole process:
Fig. 57: 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 variable "nEL2008_value" sequentially to all eight selected output bits of the EL2008 terminal. In
this way it is 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 ( ) at the yellow or
red object of the variable indicates that a link exists. The links can also be checked by selecting a "Goto Link
Variable" from the context menu of a variable. The object opposite, in this case the PDO, is automatically
selected:
EL34xx Version: 1.5 73