Eaton easySafety Manual page 494

Safety function blocks
490
The signal diagram of the function block for this application
shows the dependence of the enable contact TH01QS on the
status of coils TH01I1 and TH012:
a b
TH01I1
TH01I2
t < 500 ms
TH01QS
TH01ER
Figure 253: 1 two hand button example: Signal diagram
a Release of the two hand button, enable contact TH01QS opens.
b Renewed actuation with delayed pickup of TH01I2 < 500 ms.
c No error and enable contact TH01QS closes.
d Release of the two hand button, TH01QS opens, renewed actu-
ation and delayed pickup of TH01IS1 > 500 ms.
e Error, TH01ER closes.
f Error acknowledgement with the dropping out of TH01I1 and
TH01I2.
Example 2 - Architecture of Category 4 according to
EN ISO 13849-1
Monitoring of a 2-channel two hand button with cross-
circuit detection. Actuation of the button triggers the enable.
The two hand button S2 is connected to the device terminals
IS10 to IS13, the safety relay outputs QS1 and QS2 switch
the contactors Q1 and Q2 directly.
This looks as follows in the electrical circuit diagram:
02/16 MN05013001Z EN
c d e
t = 500 ms
f