Omron NX-SL series User Manual

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4 Safety Function Blocks
NX-series Safety Control Unit Instructions Reference Manual (Z931)
4
SF_EnableSwitch
• This FB supports stopping a safety protection function that uses an enable switch when a suitable
operation mode is started. However, handle the related operation mode (motion speed limit, power
limit, or motion range limit) outside of the SF_EnableSwitch instruction.
• This FB evaluates enable switch signals for three positions (IEC 60204 section 10.9).
•The S_EnableSwitchCh1 and S_EnableSwitchCh2 input parameters are processed as shown below
for the E1 to E4 input signal levels.
• You must connect the signals from E1 and E2 to the S_EnableSwitchCh1 parameter. You must also
connect the signals from E3 and E4 to the S_EnableSwitchCh2 parameter. The FB detects the posi-
tion of the enable switch with this signal sequence. However, the transition from position 2 to position
3 is sometimes different from the one that is shown in the figure.
• The FB can detect the direction in which the switch changed (from position 1 to position 2 or from
position 3 to position 2) by using the signal sequences that are defined for the enable switch inputs.
The FB enables stopping the safety protection function only when the switch changes from position 1
to position 2. You cannot use any other direction or switch position to enable stopping the safety pro-
tection function. This function is based on section 10.9 of IEC 60204. (The type of brackets that is
specified in EN 60204 is different).
• Because it is based on section 10.9 of IEC 60204, it is necessary to use a suitable switching device.
You must also confirm that a suitable operation mode is selected in the relevant application. (In this
operation mode, you must disable automatic operation with a suitable means.)
• An operation mode selection switch is normally used to select the operation mode to move the
machine to the safe state with the SF_ModeSelector and SF_SafeRequest instructions.
• The SF_EnableSwitch instruction confirms safe mode with the value of S_SafetyActive. If implemen-
tation does not require confirmation of safe mode in the application, connect a constant TRUE signal
to S_SafetyActive.
• Activate the S_StartReset input only when you can ensure that no hazardous state will occur as the
result of starting the Safety CPU Unit.
Function
Transitions:
(1 to 2; 2 to 1; 2 to 3)
Contacts E1 + E2
Contacts E3 + E4
Transition:
(only 3 to 1)
Contacts E1 + E2
Contacts E3 + E4
Enable Switch Positions:
1
Point of pressure
Contact
open
closed
2 3

Omron NX-SL series Specifications

General

Brand	Omron
Model	NX-SL series
Category	Control Unit
Language	English