SF_MutingSeq

Tip

The version of the function block as described here corresponds to the latest version of the function block in Version list of function blocks.

Applicable safety standards

SF_MutingSeq is a certified PLCopen function block. For detailed information about applied standards, see "PLCopen – Technical Committee 5 – Safety Software".

Important

The requirements listed in the standards must be fulfilled by the user.

Interface description

Muting is the deliberate suppression of a safety function (example: light barrier). Sequential muting with four muting sensors is specified in this block.

Table 54. VAR_INPUT

Name	Data Type	Initial Value	Description, parameter values
`Activate`	`BOOL`	`FALSE`	General input parameters
`S_AOPD_In`	`SAFEBOOL`	`FALSE`	Variable `OSSD` signal from `AOPD`. `FALSE`: Protection field interrupted. `TRUE`: Protection field not interrupted.
`MutingSwitch11`	`BOOL`	`FALSE`	Variable Status of muting sensor `MutingSwitch11`. `FALSE`: `MutingSwitch11` not damped. `TRUE`: Workpiece actuated `MutingSwitch11`. Note: Depending on the safety requirements, `SAFEBOOL` must be connected instead of `BOOL`.
`MutingSwitch12`	`BOOL`	`FALSE`	Variable. Status of muting sensor `MutingSwitch12`. `FALSE`: `MutingSwitch12` not damped. `TRUE`: Workpiece actuated `MutingSwitch 12` Note: Depending on the safety requirements, `SAFEBOOL` must be connected instead of `BOOL`.
`MutingSwitch21`	`BOOL`	`FALSE`	Variable. Status of muting sensor `MutingSwitch21`. `FALSE`: `MutingSwitch21` not actuated. `TRUE`: Workpiece actuated `MutingSwitch21`. Note: Depending on the safety requirements, `SAFEBOOL` must be connected instead of `BOOL`.
`MutingSwitch22`	`BOOL`	`FALSE`	Variable Status of muting sensor `MutingSwitch22`. `FALSE`: `MutingSwitch 22` not actuated. `TRUE`: Workpiece actuated `MutingSwitch 22` Note: Depending on the safety requirements, `SAFEBOOL` must be connected instead of `BOOL`.
`S_MutingLamp`	`SAFEBOOL`	`FALSE`	Variable or constant. Shows the state of the muting lamp. `FALSE`: Muting lamp faulty `TRUE`: Muting lamp not faulty.
`MaxMutingTime`	`TIME`	`T#0s`	Constant `0 .. 10 min`. Maximum time for complete muting sequence, timer is started when the first muting sensor is actuated. The `MaxMutingTime` caution note must be observed.
`MutingEnable`	`BOOL`	`FALSE`	Variable or constant. Command of the control system which activates the start of the muting function when required by the machine cycle. After starting the muting function, this signal can be switched off. `FALSE`: Muting not active `TRUE`: Start of the muting function activated.
`S_StartReset`	`SAFEBOOL`	`FALSE`	General input parameters
`Reset`	`BOOL`	`FALSE`	General input parameters

MaxMutingTime

For developers in Extended Level: The MaxMutingTime input has to be set to a constant value. This means that this value must not be changed for the calls.

Table 55. VAR_OUTPUT

Name	Data Type	Initial Value	Description, parameter values
`Ready`	`SAFEBOOL`	`FALSE`	General output parameters
`S_AOPD_Out`	`SAFEBOOL`	`FALSE`	Safety-oriented output, indicates the status of the non-isolating guard of the muting application. `FALSE`: `AOPD` protection field is interrupted and muting is not active. `TRUE`: `AOPD` protection field is not interrupted or muting is active.
`S_MutingActive`	`SAFEBOOL`	`FALSE`	Displays the status of the muting process. `FALSE`: Muting not active `TRUE`: Muting active
`Error`	`BOOL`	`FALSE`	General output parameters
`DiagCode`	`WORD`	`16#0000`	Diagnostic codes

Important

A short circuit in the muting sensor signals, or a functional application error in supporting these signals, is not supported by this function block, but is interpreted as an incorrect muting sequence. (Data type BOOL, supplied by the functional user hardware or software.) Nevertheless, this should not lead to unwanted muting. Users should consider this in their respective risk analyses.

Figure 85. Function block: SF_MutingSeq

Functional description

Muting is the deliberate suppression of a safety function. This is necessary, for example, when material is to be transported into the hazardous area without causing the machine to stop. Muting is triggered by a muting sensor. The use of two or four muting sensors and the correct integration into the production process has to ensure that no person enters the hazardous area while the light grid is muted. Muting sensors can be proximity switches, photoelectronic barriers, limit switches, etc. which do not have to be fail-safe. Active muting mode has to be indicated by indicator lamps.

There are sequential and parallel muting methods. Sequential muting with four muting sensors is used in this block. An execution of the forward direction of transport is listed below. The FB can be used in both directions: forward and backward. Muting should be activated by the MutingEnable signal from the process to prevent tampering. If the MutingEnable signal is not available, then the input has to be set to TRUE.

The input parameters of the function block include the signals of the four muting sensors (MutingSwitch11, MutingSwitch12, MutingSwitch21, and MutingSwitch22), as well as the OSSD signal of the "active opto-electronic protective device" S_AOPD_In.

Caution

The S_StartReset input shall only be activated if it is ensured that no hazardous situation can occur when the S-PLC is started.

Table 56. Example of SF_MutingSeq in forward direction with four sensors

No.	Image	Explanation
1		If the muting sensor `MutingSwitch12` (`MS_12`) is actuated by a workpiece after `MutingSwitch11` `(MS12`), then the muting mode is activated.
2		Muting mode remains active as long as `MutingSwitch11` `(MS11`) and `MutingSwitch12` `(MS_12`) are actuated by the workpiece. The workpiece can pass through the light grid without causing a machine stop.
3		Before the muting sensors `MutingSwitch11` (`MS_11`) and `MutingSwitch12` (`MS_12`) are deactivated, `MutingSwitch21` (`MS_21`) and `MutingSwitch22` (`MS_22`) have to be activated. This ensures that the muting mode remains active.
4		Muting mode is ended when only muting sensor `MutingSwitch22` (`MS_22`) is actuated by the workpiece.

Status diagram

Figure 86. Status diagram: SF_MutingSeq

Tip

Note: The transition from any state to the Idle state, initiated by Activate = FALSE, is not shown. In every case, these transitions have the highest priority.

Typical timing diagram

Figure 87. Timing diagram SF_MutingSeq with S_StartReset = TRUE

Muting conditions

. Forward direction

Muting condition 1 (to status 16#8011) (MS_11 is the first actuated input sensor). Start timer: MaxMutingTime:
MutingEnable AND (R_TRIG at MS_11 AND NOT MS_12 AND NOT MS_21 AND NOT MS_22)
Muting condition 2 (from status 16#8011 to 16#8012) (MS_12 is the second actuated input sensor):
MutingEnable AND (MS_11 AND R_TRIG at MS_12 AND NOT MS_21 AND NOT MS_22)
Muting condition 3 (from status 16#8012 to 16#8000) (MS_21 first actuated output sensor). Stop timer: MaxMutingTime:
NOT MS_11 AND NOT MS_12 AND F_TRIG at MS_21 AND MS_22

. Backward direction

Muting condition 11 (to status 16#8122) (MS_22 is the first actuated input sensor). Start timer: MaxMutingTime:
MutingEnable AND (NOT MS_11 AND NOT MS_12 AND NOT MS_21 AND R_TRIG at MS_22)
Muting condition 12 (from status 16#8122 to 16#8112) (MS_21 is the second actuated input sensor):
MutingEnable AND (NOT MS_11 AND NOT MS_12 AND R_TRIG at MS_21 AND MS_22)
Muting condition 13 (MS_12 the first actuated output sensor). Stop timer: MaxMutingTime:
MS_11 AND F_TRIG at MS_12 AND NOT MS_21 AND NOT MS_22

. Specification of incorrect muting sequences:

In status 16#8000: (NOT MutingEnable AND R_TRIG at MS_11) OR (NOT MutingEnable AND R_TRIG at MS_22) OR (MS_12 OR MS_21) OR (MS_11 AND MS_22)
In status 16#8011: NOT MutingEnable OR NOT MS_11 OR MS_21 OR MS_22
In status 16#8012: R_TRIG at MS_11 OR R_TRIG at MS_12 OR F_TRIG at MS_22
In status 16#8122: NOT MutingEnable OR MS_11 OR MS_12 OR NOT MS_22
In status 16#8112: F_TRIG at MS_11 OR R_TRIG at MS_21 OR R_TRIG at MS_22

Error detection

The FB detects the following error conditions:

The muting sensors MutingSwitch11, MutingSwitch12, MutingSwitch21, and MutingSwitch22 are activated in the wrong order.
Muting sequence starts without activation by MutingEnable.
A faulty muting lamp is indicated by S_MutingLamp = FALSE.
A static Reset condition.
MaxMutingTime was set to a value less than zero or greater than T#10min.
The muting function (S_MutingActive = TRUE) exceeds the maximum muting time MaxMutingTime.

Error behavior

In case of an error event, the outputs S_AOPD and S_MutingActive are set to FALSE. The DiagCode output displays the relevant error code and the Error output is set to TRUE.

A restart is prevented until the error conditions are clarified and the safe state is confirmed with Reset.

FB-specific error and status codes

Table 57. FB-specific error codes

`DiagCode`	Statue Name	Status description and output setting
`16#C001`	`Reset Error 1`	Static Reset condition detected after FB activation `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = TRUE`
`16#C002`	`Reset Error 2`	Static reset condition detected in status `16#8003` `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = TRUE`
`16#C003`	`Error Muting Lamp`	Error detected with muting lamp `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = TRUE`
`16#CYx4`	`Error Muting sequence`	Error in muting sequence in status `16#8000, 16#8011, 16#8012,16#8112` or `16#8122` `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = TRUE` `Y` = status in the sequence (2 statuses for forward direction and 6 statuses for backward direction). `16#C0x4` = Error occurs in status `16#8000`. `16#C1x4` = Error occurs in forward status `16#8011`. `16#C2x4` = Error occurs in forward status `16#8012`. `16#C3x4` = Error occurs in backward status `16#8122`. `16#C4x4` = Error occurs in backward status `16#8112`. `16#CFx4` = Muting Enable missing `x` = status of the sensor when an error occurs (4 bits: `LSB = MS_11`; `MS_12`; `MS_21`; `MSB = MS_22`).
`16#C005`	`Parameter Error`	`MaxMutingTime` value out of valid range. `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = TRUE`
`16#C006`	`Error Timer MaxMuting`	Timing error: Active muting time (if `S_MutingActive = TRUE`) exceeds `MaxMutingTime`. `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = TRUE`

Table 58. FB-specific status codes

`DiagCode`	Statue Name	Status description and output setting
`16#0000`	`Idle`	The function block is not active (basic state). `Ready = FALSE` `S_AOPD_Out =FALSE` `S_MutingActive = FALSE` `Error = FALSE`
`16#8000`	`AOPD`	Muting not active and no safety requirement from `AOPD`.
`16#8001`	`Init`	The block has been activated. `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = FALSE`
`16#8002`	`Safety Demand AOPD`	Safety request detected by `AOPD`, muting not active. `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = FALSE`
`16#8003`	`Wait for Reset`	Safety requirement or error was discovered and is now cleared. Confirmation `Reset` requested. `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = FALSE`
`16#8005`	`Safe`	Safety function activated `Ready = TRUE` `S_AOPD_Out = FALSE` `S_MutingActive = FALSE` `Error = FALSE`
`16#8011`	`Muting Forward Start`	Muting forward sequence is in the start phase, no safety requirement `Ready = TRUE` `S_AOPD_Out = TRUE` `S_MutingActive =FALSE` `Error = FALSE`
`16#8012`	`Muting Forward Active`	Muting forward sequence is active. `Ready = TRUE` `S_AOPD_Out = TRUE` `S_MutingActive = TRUE` `Error = FALSE`
`16#8112`	`Muting Backward Active`	Muting backward sequence is active. `Ready = TRUE` `S_AOPD_Out = TRUE` `S_MutingActive = TRUE` `Error = FALSE`
`16#8122`	`Muting Backward Start`	Muting backward sequence is in the start phase, no safety requirement `Ready = TRUE` `S_AOPD_Out = TRUE` `S_MutingActive = FALSE` `Error = FALSE`