BECKHOFF EL6900-FB - Manual (Page 48)

Function blocks
46 Function blocks for TwinSAFE logic terminals
3.7 The TWO-HAND function block
3.7.1 Functional description
The FB TWO-HAND is used to realize a two-hand control unit in which both input groups have to be
operated simultaneously in order to switch the output. Repeated setting of the output is only possible if
both input groups were on logic 0 at the same time.
An input group can be configured as a single-channel input, two-channel input or two-channel input with
discrepancy time monitoring. In addition, time monitoring up to 2500 ms between the two input groups
can be defined. Each input can be configured as normally closed contact (NC) or normally open contact
(NO).
Figure 3-13: TWO-HAND function block
Note
KL6904
The two-hand block is not available in the KL6904.