SF_SafetyRequestPermalink

This is the web edition of the original ‎⮫ AC500-S safety user manual, version 1.3.2. This web edition is provided for quick reference only. The original safety user manual must be used to meet functional safety application requirements.

Standards

Requirements

IEC 60204-1:2016

9.3.6 Suspension of safety functions and/or protective measures

Where it is necessary to suspend safety functions and/or protective measures (e.g., for setting or maintenance purposes), protection shall be ensured by:

  • disable all other operating (control) modes;

  • permit operation only by the use of a hold-to-run device or by a similar control device positioned so as to permit sight of the hazardous elements;

  • permit operation of the hazardous elements only in reduced risk conditions (e.g., reduced speed, reduced power / force, step-by-step operation, e.g., with a limited movement control device);

  • prevent any operation of hazardous functions by voluntary or involuntary action on the machine’s sensors.

ISO 13849-1:2015

5.2.2 Manual reset function

ISO 12100:2010

6.2.11.2 Starting of an internal power source/switching on an external power supply

6.2.11.4 Restart after power interruption

SF_SafetyRequest

This function block provides the interface to a generic actuator, e.g., a safety drive or safety valve, to place the actuator in a safe state.

This FB provides the interface between the safety-related system and a generic actuator. This means that the safety-related functions of the actuator are available within the application program. However, there are only two binary signals to control the safe state of the generic actuator, i.e., one for requesting and one for receiving the confirmation.

The safety function will be provided by the actuator itself. Therefore, the FB only initiates the request, monitors it, and sets the output when the actuator acknowledges the safe state. This will be indicated with the "S_SafetyActive" output.

This FB does not define any generic actuator-specific parameters. They should have been specified in the generic actuator itself. It switches the generic actuator from the operation mode to a safe state.

The additional input S_StartReset offers the possibility of an automatic cold start as it is defined for the other FBs.

Table 1120: FB name: SF_SafetyRequest

Name

Data type

Initial value

Description, parameter values

VAR_INPUT

Activate

BOOL

FALSE

⮫ Table 1058 “General input parameters”

S_OpMode

BOOL

FALSE

Variable.

Requested mode of a generic safe actuator.

FALSE: Safe mode is requested.

TRUE: Operation mode is requested.

S_Acknowledge

BOOL

FALSE

Variable.

Confirmation of the generic actuator, if actuator is in the safe state.

FALSE: Operation mode (non-safe).

TRUE: Safe mode.

S_StartReset

BOOL

FALSE

⮫ Table 1058 “General input parameters”

Reset

BOOL

FALSE

⮫ Table 1058 “General input parameters” with the functionality as an error removed acknowledge.

MonitoringTime

TIME

T#0s

Constant.

Monitoring of the response time between the safety function request (S_OpMode set to FALSE) and the actuator acknowledgment (S_Acknowledge switches to TRUE).

VAR_OUTPUT

Ready

BOOL

FALSE

⮫ Table 1059 “General output parameters”

S_SafetyActive

BOOL

FALSE

Confirmation of the safe state.

FALSE: Non-safe state.

TRUE: Safe state.

S_SafetyRequest

BOOL

FALSE

Request to place the actuator in a safe state.

FALSE: Safe state is requested.

TRUE: Non-safe state.

SafetyDemand

BOOL

FALSE

Optional.

⮫ Table 1059 “General output parameters”

ResetRequest

BOOL

FALSE

Optional.

⮫ Table 1059 “General output parameters”

Error

BOOL

FALSE

⮫ Table 1059 “General output parameters”

DiagCode

WORD

16#0000

⮫ Table 1059 “General output parameters”

The function block represents the interface between the user program and system environment.

Fig. 511: Example of SF_SafetyRequest

Example_SF_SafetyRequest

Typical timing diagram

Fig. 512: Typical timing diagram for SF_SafetyRequest

SF_SafetyRequest_TimingDiagram

Error detection

The FB detects whether the actuator does not enter the safe state within the monitoring time.

The FB detects whether the acknowledge signal is lost while the request is still active.

The FB detects a static Reset signal.

External FB errors: There are no external errors, since there is no error bits/information provided by the generic actuator.

Error behavior

In the event of an error, the S_SafetyActive output is set to FALSE.

An error must be acknowledged by a rising trigger at the Reset input. To continue the function block after this reset, the S_OpMode request must be set to TRUE or S_Acknowledge must become TRUE.

Function block-specific error and status codes

Table 1121: FB-specific error codes

DiagCode

State name

State description and output setting

C010

Acknowledge Lost

Acknowledgment lost while in the safe state.

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = TRUE

Error = TRUE

C020

MonitoringTime Elapsed

S_OpMode request could not be completed within the monitoring time.

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = TRUE

Error = TRUE

C001

Reset Error 1

Static reset detected in state 8401 (Init).

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = TRUE

C014

Reset Error 2

Static reset detected in state C002 (Acknowledge Lost).

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = TRUE

C011

Reset Error 3

Static reset detected in state C003 (MonitoringTime elapsed).

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = TRUE

Table 1122: FB-specific status codes (no error):

DiagCode

State name

State description and output setting

0000

Idle

The function block is not active (initial state).

Ready = FALSE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = FALSE

8000

Safe Mode

Actuator is in a safe mode.

Ready = TRUE

S_SafetyActive = TRUE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = FALSE

8401

Init

State after Activate is set to TRUE or after a rising trigger at Reset.

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = TRUE

Error = FALSE

8802

Operation Mode

Operation mode without Acknowledge of safe mode.

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = TRUE

SafetyDemand = TRUE

ResetRequest = FALSE

Error = FALSE

8804

Wait for Confirmation OpMode

Operation mode with Acknowledge of safe mode.

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = TRUE

SafetyDemand = TRUE

ResetRequest = FALSE

Error = FALSE

8002

Wait for Confirmation

Waiting for confirmation from the drive (system interface).

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = FALSE

8004

Wait for OpMode

Error was removed. However, S_OpMode must be set to TRUE or S_Acknowledge must become TRUE before the FB can be continued.

Ready = TRUE

S_SafetyActive = FALSE

S_SafetyRequest = FALSE

SafetyDemand = FALSE

ResetRequest = FALSE

Error = FALSE