SIMATIC SAFETY MATRIX

Introduction:

This article will continue previous articles PCS7 SIMATIC SAFETY MATRIX. In previous articles we are enables to work on Simatic Safety Matrix. In this article, we will talk in detail about Simatic Safety Matrix.

Pre-requisites

The learner should have read my previous article on PCS7 SIMATIC SAFETY MATRIX.

Safety integrity level (SIL):

Let's start with short discussion on Safety Integrity Level (SIL). As you open the properties of F-DO Card, you will find Safety Mode (SIL3) in parameter tab.

Safety Integrity Level (SIL) is a critical concept in the field of industrial safety and risk management. SIL is typically categorized into four levels, from SIL 1 (lowest) to SIL 4 (highest). In Siemens card you will find SIL 1 to 3, and it depend upon the card. Each SIL level corresponds to a specific range of risk reduction, measured in terms of the probability of a hazardous event occurring. SIL 1 provides the least risk reduction, while SIL 4 offers the highest. The selection of the appropriate SIL level for a specific application is determined through a thorough risk assessment, considering factors such as the nature and severity of potential hazards, the likelihood of their occurrence, and the potential consequences. The goal is to ensure that the safety system is capable of reducing the risk to an acceptable level.

We select SIL3 because we are using redundant card and each card channels have redundant channels, which means for one signal we have two cards and two channels.

EVALUTION OF SENSORS:

If you open the properties of F-DI Card, you will find Evalution of the sensors 1oo1 Evalution.

You can set the type of sensor evaluation in safety mode:

• 1oo1 evaluation
• 1oo2 evaluation

1oo1 evaluation

In 1oo1 evaluation, there is one sensor that is connected to the module via a single channel.

1oo2 evaluation

In 1oo2 evaluation, there is one sensor that is connected to the module via a two channel. In 1oo2 evaluation, two channels are combined into a channel pair. The number of input channels available in the fail-safe module is reduced accordingly.

Working on CFC's:

After transfer of Simatic Safety Matrix, CFC is generated with matrix name, as you open you will find two nested charts as shown in picture.

Nested chart of the F-channel drivers ("Matrix(1)"):

In this nested chart, the Simatic Safety Matrix automatically place driver F-Channels of Fail-to-safe cards. As you can see in given picture.

Input PASS_ON is interconnected with input PASS_ON of all internal F-channel drivers. By interconnecting this input, you can passivate all F-channel drivers of the Safety Matrix, e.g., if you want to enable passivation as a function of particular states in your safety program.

Nested chart of the matrix logic ("@Matrix(1)"):

This nested chart is protected and cannot be open. It contains logic of safety program.

This nested chart has default some visible bits which are as under:

MatrixSig: Contains the Safety Matrix signature.

EN_SWC: This input (F_BOOL) can be used to enable and, if necessary, to disable the Secure Write function for the purpose of making operator inputs either in online mode of the engineering tool or from the PCS 7 OS. This takes place by means of a signal that is wired in the CFC prior to compiling (enable, if signal = TRUE).

EN_GDM and SET_GDM: With these two inputs of the F_BOOL type all active maintenance operations for Causes/Effects, such as simulations, soft bypasses and override functions, can be deactivated with one external signal, e.g. over a key switch. Deactivation can take place even if this is no longer possible online because visualization is no longer available.

Error: Boolean flag indicating that an error was detected in the safety data format.

Any_CA: Indicates that at least one of the Causes in the Safety Matrix is active.

Any_EA: Indicates that at least one of the effects in the Safety Matrix is active.

CByp_Num: Integer value indicating how many Causes are currently bypassed.

EByp_Num: Integer value indicating how many effects are currently bypassed.

Msec: Current processing time of the Safety Matrix including F-channel drivers in the nested chart of F-channel drivers ("Matrix(1)")

MaxMsec: Maximum processing time of the Safety Matrix including F-channel drivers in the nested chart of F-channel drivers ("Matrix(1)") This output is reset again to 0 on each startup of the Safety Matrix.

Acknowledgement:

During the working on Simatic Safety Matrix, we checked the auto acknowledge, when we were selecting driver channel or cause and effect. It will automatically be connecting F-Channel for ACK_REI as shown in the picture.

For spare channel we can off the diagnostics from F-Cards properties or we can make logic for acknowledgement. we have to select F-Driver channel from catalog and assigning its hardware address, the connecting blocks as shown in picture.

The out of F_BO_FBO will connect with ACK_REI of spare driver channels. After compiling, it will automatically connect CHADDR and CHADDR_R as shown in picture.

To Sum It Up:

In previous articles PCS7 SIMATIC SAFETY MATRIX, we learned how to work on Simatic Safety Matrix with an example. In this article we learned about SIL level, Evalution of sensor and further dug in nested chart.

Thank You:

I hope you found this article informative and useful. I'm eager to hear your thoughts and experiences in the comments section below. If you have any questions or would like to connect further, feel free to send me a connection request. Thank you for reading!"