Chapter 9 
204 
Logic programming – Function blocks 
 
9.9.11  Multi operator (multiple two-hand control) 
Function block diagram 
 
 
General description 
The Multi operator function block is used to monitor simultaneous operation of up to 
three two-hand controls. For example, several two-hand controls or foot switches can 
be necessary in a press application with more than one operator in order to trigger the 
downward movement of the press. Typically, each Operator input is connected to a 
Two-hand control function block. 
Release inputs (e.g. safety light curtains) can be connected optionally in order to 
ensure that the assigned devices are High before the Enable output can become High. 
Resetting and restarting need to be handled independently of this function block. 
The Cycle request input can be used to enforce that each connected two-hand 
control is released at least once before another start is possible. Typically this input is 
connected to a signal that generates a pulse with each machine cycle. In this way it 
can be prevented that one or more of the two-hand controls remain actuated 
permanently. 
The Operator inputs and the Release inputs must be pre-evaluated signals! 
  Connect only safe pre-evaluated signals to the Operator inputs, e.g. the Enable 
output of a Two-hand control type IIIA or Two-hand control type IIIC function block. 
A safety-relevant evaluation of the inputs of a two-hand control has to be effected 
either by another function block (e.g. Two-hand control or Light curtain monitoring) 
or as a part of the configuration of the safety inputs (e.g. configuration of the inputs 
with dual-channel evaluation). 
 The Cycle request input must not be used for safety functionality. This input is for 
automation control functionality only. 
 
Parameters of the function block 
Parameter  Possible values 
Cycle request condition   Rising edge 
 Falling edge 
Number of operators   2 operators 
 3 operators 
Number of static releases   0 
 1 
 2 
 
Figure 194: 
Function block diagram for 
the Multi operator function 
block 
 
ATTENTION 
Table 91: 
Parameters for the Multi 
operator function block