Epec Programming and Libraries Manual
Click here to see this page in full context

Supported platforms: CODESYS 3.5, CODESYS 3.5 SAFETY

 

S_ValidateSRDO_<type> (FB)

Description

These function blocks validate diverse SRDO message data to single safe type variable. Outdated or mismatching data is diagnosed.

The plain and binary-inverted input data are compared to match.

The timestamp input values are the CAN message reception time µs-values from firmware.

If the given Safety Cycle Time or Safety-Related Validation Time has passed, or the input data mismatch, the data is considered invalid.

 

 

Each supported variable type has a function block.

 

Function

Data type of i_PlainMsgData and i_InvertMsgData

Data type of S_o_Output

S_ValidateSRDO_BYTE

BYTE

SAFEBYTE

S_ValidateSRDO_WORD

WORD

SAFEWORD

S_ValidateSRDO_DWORD

DWORD

SAFEDWORD

S_ValidateSRDO_SINT

SINT

SAFESINT

S_ValidateSRDO_INT

INT

SAFEINT

S_ValidateSRDO_DINT

DINT

SAFEDINT

S_ValidateSRDO_USINT

USINT

SAFEUSINT

S_ValidateSRDO_UINT

UINT

SAFEUINT

S_ValidateSRDO_UDINT

UDINT

SAFEUDINT

 

Initialization

Init method is used to initialize the necessary static calculation parameters for the function block instance.

The method shall be called at least once before the actual function block can be called, i.e. at the application initialization phase.

The method checks the validity of input parameters. However, none of the function block outputs are affected by the initialization.

 

A parameter error is diagnosed if:

• Init method is not called before the main FB call OR

• S_i_SRVTime = 0 OR

• i_pEventCode = 0 OR

• i_pTrigger = 0 OR

• i_pInterlock = 0 OR

• i_SRDOIndex out of range OR

• i_VarIndex out of range

 

 

SRDO uses EventCode’s DeviceID as SRDO number and ChannelID as mapped variable index. The values are given as input parameters at initialization. Thus variable validation can use the same EventCode instance for SRDO as safety signature validation.

 

Initialization parameters

Parameter

Type

Unit

Range

Description

S_i_SCTime

SAFEUINT

ms

-

Safeguard cycle time of the SRDO.

S_i_SRVTime

SAFEUSINT

ms

>0

SR validation time of the SRDO.

i_SRDOIndex

BYTE

-

1..64

SRDO index number to be added to EventCode as DeviceID.

i_VarIndex

BYTE

-

1..8

Index number of mapped variable in SRDO. To be added to EventCode as ChannelID.

i_pEventCode

POINTER TO EventCode

-

≠0

Pointer to application variable which is type EventCode.

i_pTrigger

POINTER TO BOOL

-

≠0

Pointer to boolean variable that triggers the validation procedure.

i_pInterlock

POINTER TO BOOL

-

≠0

SRDO interlock from CANopen

 

Initialization method return value

TRUE: All initialization parameters ok.

FALSE: Error in initialization parameter(s).

 

 

Operation

CANopen library SRDO reception sets a global trigger status TRUE when inverted message is received.

When enabled (i.e. the system is operational), the function block waits for the trigger status to be TRUE (i_pTrigger) to start the validation procedure.

Validated i_PlainMsgData value is copied to S_o_Output if:

• The control is enabled, i.e. i_Enable is TRUE, AND

• New data is available, i.e. trigger is TRUE, AND

• No fault (including initialization) has been diagnosed

 

Successful reception of an SRDO variable is signaled by o_Status.OutputValid.

Operation between safety and non-safety tasks

A safe application runs safe and non-safe tasks. Due to lower priority, the non-safe task may be interrupted at any time by the safe task.

If an interrupt occurs while the application is handling diverse non-safe SRDO data, the validation will fail.

 

The non-safe CANopenSRDO protocol handler keeps the global lock status TRUE (given in i_pInterlock parameter) while handling received message data. The validation function blocks use global lock status to disable safety cycle and SR validation timeout diagnostic.

Operation in fault situations

The output S_o_Output is set to 0 and o_Status.SCTimeOut is set TRUE if:

• i_Enable is TRUE, and pointed trigger status has not been set for given safeguard cycle time S_i_SCTime OR

• Time between current and previous received message time i_InvertMsgTime is greater than given safeguard cycle time S_i_SCTime

 

The output S_o_Output is set to 0 and o_Status.SRVTimeOut is set TRUE if:

• i_InvertMsgTime - i_PlainMsgTime > S_i_SRVTime (time between messages in pair too long) OR

• i_InvertMsgTime - i_PlainMsgTime < 0 (messages received in inconsistent order)

 

The output S_o_Output is set to 0 and o_Status.DataMismatch is set TRUE if:

• Any i_InvertMsgData bit = i_PlainMsgData bit

 

All function block statuses, including errors are reset on rising edge of i_Enable.

Limitations

SRDO protocol is supported in CANopen library version 4.0.0.0 or newer.

 

SRDO message's refresh time (tx interval) shall be greater than 2x safety task's cycle time for SRDO to work properly with interlock functionality.

Inputs

Input variable name

Data type

Unit

Range

Description

i_Enable

BOOL

-

-

Enable POU operation

i_PlainMsgData

<type>

-

-

Plain SRDO message data

i_PlainMsgTime

UDINT

µs

-

Plain SRDO message time

i_InvertMsgData

<type>

-

-

Invert SRDO message data

i_InvertMsgTime

UDINT

µs

-

Invert SRDO message time

Outputs

Output variable name

Data type

Range

Description

S_o_Output

<type>

-

Validated variable value

o_Status

Status

-

Status of output value

Error diagnostic

See Diagnostic Interface library description of error status and event code functionality.

 

Conditions

S_o_Output value

o_Status. OutputValid

o_Status error status

Event code FunctionID

Event code EventID

i_Enable TRUE

AND

init parameter error AND

 i_pEventCode valid

0

FALSE

ParameterError

VALIDATE_SRDO

PARAMETER_ERROR

i_Enable TRUE

AND

init parameter error AND
i_pEventCode NULL

0

FALSE

ParameterError

-

-

i_Enable rises

AND

 init parameters ok AND

data not validated

0

FALSE

-

NO_FUNC

NO_ERROR

i_Enable TRUE

AND

parameters ok

AND

data validated

AND

plain data match inverted data

the last validated plain message data

TRUE

-

NO_FUNC

NO_ERROR

i_Enable TRUE

AND

 parameters ok

AND

plain data mismatch inverted data

0

FALSE

ValueMismatch

VALIDATE_SRDO

DATA_MISMATCH

i_Enable TRUE

AND

 parameters ok

AND

plain data match inverted data

AND

i_pInterlock^ TRUE AND
time between plain and inverted messages > S_i_SRValidationTime

the last validated plain message data

TRUE

-

NO_FUNC

NO_ERROR

i_Enable TRUE

AND

 parameters ok

AND

plain data match inverted data

AND

i_pInterlock^ FALSE

AND
time between plain and inverted messages > S_i_SRValidationTime

0

FALSE

SRVTimeout

VALIDATE_SRDO

SRV_TIMEOUT

i_Enable TRUE

 AND

 parameters ok

AND

plain data match inverted data

AND

i_pInterlock^ TRUE AND
time between two consecutive inverted messages > S_i_SafetyCycleTime

the last validated plain message data

TRUE

-

NO_FUNC

NO_ERROR

i_Enable TRUE

 AND

 parameters ok

AND

plain data match inverted data

AND

i_pInterlock^ FALSE AND
time between two consecutive inverted messages > S_i_SafetyCycleTime

0

FALSE

SCTimeout

VALIDATE_SRDO

SC_TIMEOUT

i_Enable TRUE

AND

 parameters ok

AND

plain data match inverted data

AND
trigger has been FALSE > S_i_SafetyCycleTime

0

FALSE

SCTimeout

VALIDATE_SRDO

SC_TIMEOUT

 

Example code

SRDO related POUs are automatically generated to code template when MultiTool is used.

 

 

 

Definitions:

 

(*NOTE! This object is created by Epec MultiTool Creator*)

 

/// SRDO variables

/// Plain SRDO variables

rdw1 AT %MD4: DWORD := DWORD#16#0;

rdw2 AT %MD5: DWORD := DWORD#16#0;

/// Inverted SRDO variables

rdw1_i AT %MD6: DWORD := DWORD#16#0;

rdw2_i AT %MD7: DWORD := DWORD#16#0;

/// Plain SRDO variable timestamps

rdw1_TIME: UDINT := UDINT#0;

rdw2_TIME: UDINT := UDINT#0;

/// Inverted SRDO variable timestamps

rdw1_i_TIME: UDINT := UDINT#0;

rdw2_i_TIME: UDINT := UDINT#0;

 

/// SRDO variable mappings

SRDO2Mappings: ARRAY [1..G_CANOPEN_NUMBER_OF_LAST_SRDO_MAP*2] OF DWORD := [

DWORD#16#5FD60320, (* rdw1 *)

DWORD#16#5FD50320, (* rdw1_i *)

DWORD#16#5FD60420, (* rdw2 *)

DWORD#16#5FD50420, (* rdw2_i *)

12(DWORD#16#0)]; (* 16 - 4 = 12 *)

 

/// CANopen common

Device: EPEC_CANopen.Device;

Protocols: ARRAY[1..6] OF EPEC_CANopen.ProtocolEntry;

ProtocolAdded: ARRAY[1..6] OF BOOL := [6(0)];

 

/// SRDO

SRDO: EPEC_CANopen.SRDOData; (* Protocol data *)

SRDOS: ARRAY[1..2] OF EPEC_CANopen.CANopenSRDO; (* SRDO instances *)

SRDO_Handler: EPEC_CANopen.CANopenSRDOHandler; (* Protocol handler *)

SRDO_Error: EPEC_CANopen.Errors := EPEC_CANopen.Errors.NotInitialized;

SRDO_Triggers: ARRAY[1..2] OF BOOL;

SRDO_Signatures: ARRAY[1..2] OF WORD;

SRDO_EventCodes: ARRAY[1..2] OF EPEC_DITF.EventCode;

SRDO_Interlock: ARRAY[1..2] OF BOOL;

 

 

Init:

 

(*NOTE! This object is created by Epec MultiTool Creator*)

 

 

 

(*Define SRDO protocol*)

Protocols[6].Protocol:=EPEC_CANopen.ProtocolType.SRDO;

Protocols[6].pData:=ADR(SRDO);

Protocols[6].itfProtocol:=SRDO_Handler;

Protocols[6].pError:=ADR(SRDO_Error);

ProtocolAdded[6] := CANopenDeviceAddProtocol( (* Add to protocol stack *)

    i_pDevice:=ADR(Device),

    i_pProtocol:=ADR(Protocols[6])

);

IF ProtocolAdded[6] THEN

    SRDO_Handler.Init(

        i_pDevice := ADR(.Device)

    );

ELSE

    SRDO_Error := EPEC_CANopen.Errors.ProtocolDataMissing;

END_IF

 

 

 

(* Init SRDOs *)

SRDOS[2].i_pTimings[1]:= ADR(rdw1_TIME); (*rdw1 *)

SRDOS[2].i_pTimings[2]:= ADR(rdw1_i_TIME); (*rdw1_i *)

SRDOS[2].i_pTimings[3]:= ADR(rdw2_TIME); (*rdw2 *)

SRDOS[2].i_pTimings[4]:= ADR(rdw2_i_TIME); (*rdw2_i *)

SRDOS[2].Init(

    i_pDevice := ADR(Device),

    i_SRDONumber := 2,

    i_SRDOType := EPEC_CANopen.SRDOType.ReceiveSRDO,

    i_SCTime := UINT#50, (* RSRDO Safeguard Cycle Time (ms) *)

    i_SRVTime := USINT#20, (* Validation time (rx) (ms) *)

    i_COB_ID1 := DWORD#16#103, (* Plain message COB-ID *)

    i_COB_ID2 := DWORD#16#104, (* Inverted message COB-ID *)

    i_Mapping := G_CANopen_CAN1_Mappings.SRDO2Mappings, (* Plain + Inverted data mappings *)

    i_Mappings := 4, (* Plain + Inverted data mappings *)

    i_pTriggerValidation := ADR(SRDO_Triggers[2]), (* Trigger status *)

    i_pInterlock := ADR(SRDO_Interlock[2]),

    o_Error => SRDO_Error

);

 

 

Code:

 

 

(*NOTE! This object is created by Epec MultiTool Creator*)

 

// Update protocol data

G_CANopen_CAN1.SRDO_Handler.Update(

    i_Enable := TRUE, (*Enable condition is set by MultiTool Creator code template*)

    o_Error => SRDO_Error

);

 

 

Definitions:

 

(*NOTE! This object is created by Epec MultiTool Creator*)

 

PROGRAM S_Validate_SRDOs_CAN1

VAR_INPUT

i_Enable: BOOL := FALSE;

i_Initialize:BOOL:=TRUE;

END_VAR

VAR_OUTPUT

/// Safe variables received over SRDO

S_o_rdw1: SAFEDWORD := DWORD#0;

S_o_rdw2: SAFEDWORD := DWORD#0;

/// SRDO validation FB statuses

o_SRDO_2_Valid: BOOL;

 

END_VAR

VAR

/// SRDO validation FB instances

S_Validate_rdw1: EPEC_SRDO.S_ValidateSRDO_DWORD;

S_Validate_rdw2: EPEC_SRDO.S_ValidateSRDO_DWORD;

 

Status_rdw1: EPEC_SRDO.Status;

Status_rdw2: EPEC_SRDO.Status;

 

END_VAR

 

 

Init:

 

(*NOTE! This object is created by Epec MultiTool Creator*)

 

// SRDO 1 data

rxSRDO_Ok := S_Validate_rw1.Init(

    S_i_SCTime := SRDOS[2].i_SCTime, (* Safeguard cycle time *)

    S_i_SRVTime := SRDOS[2].i_SRVTime, (* SR Validation time *)

    i_SRDOIndex := BYTE#2, (* SRDO number -> EventCode.DeviceID *)

    i_VarIndex := BYTE#1, (* variable number -> EventCode.ChannelID *)

    i_pEventCode := ADR(SRDO_EventCodes[2]), (* Event code pointer for FB *)

    i_pTrigger := ADR(SRDO_Triggers[2]), (* Trigger status *)

    i_pInterlock := ADR(SRDO_Interlock[2])

);

rxSRDO_Ok := rxSRDO_Ok AND S_Validate_rw2.Init(

    S_i_SCTime := SRDOS[2].i_SCTime, (* Safeguard cycle time *)

    S_i_SRVTime := SRDOS[2].i_SRVTime, (* SR Validation time *)

    i_SRDOIndex := BYTE#2, (* SRDO number -> EventCode.DeviceID *)

    i_VarIndex := BYTE#2, (* variable number -> EventCode.ChannelID *)

    i_pEventCode := ADR(SRDO_EventCodes[2]), (* Event code pointer for FB *)

    i_pTrigger := ADR(SRDO_Triggers[2]), (* Trigger status *)

    i_pInterlock := ADR(SRDO_Interlock[2])

);

 

 

Application must reset SRDO message trigger after validation.

 

Code:

 

(*NOTE! This object is created by Epec MultiTool Creator*)

 

// SRDO 1 data

(* Validate RX SRDO data *)

S_Validate_rdw1(

    i_Enable := i_Enable,

    i_PlainMsgData := rdw1,

    i_InvertMsgData := rdw1_i,

    i_PlainMsgTime := rdw1_TIME,

    i_InvertMsgTime := rdw1_i_TIME,

    o_Status => Status_rdw1,

    S_o_Output => S_o_rdw1

);

S_Validate_rdw2(

    i_Enable := i_Enable,

    i_PlainMsgData := rdw2,

    i_InvertMsgData := rdw2_i,

    i_PlainMsgTime := rdw2_TIME,

    i_InvertMsgTime := rdw2_i_TIME,

    o_Status => Status_rdw2,

    S_o_Output => S_o_rdw2

);

 

SRDO_Triggers[2]:=FALSE;       // reset SRDO message trigger

 

o_SRDO_2_Valid := Status_rdw1.OutputValid AND

                  Status_rdw2.OutputValid;

 

 

 

Example architecture

See also