Diagnostic FBs for safety-related Up-/Downstream Communication

In a safety-related application, the safety-related communication and the operational state of safety-related devices should be monitored. This enables the Safety PLC to determine the state of the functional safety system. In case of a safety-related device/communication error, the machine must enter the defined safe state.

The prerequisite for using the FBs is the use of control type SPLC1000 from Fimware version 3.0.

WARNING

Unintended machine operation

Make sure that your risk analysis includes a possible temporary or permanent malfunction of a safety-related device/module or of the communication between devices and the Safety PLC.

Use either the diagnostic function blocks described here, or the relevant diagnostic system variables provided by the Safety PLC to monitor the status of the PROFIsafe/FSoE communication between F-Host and the F-Devices involved in your safety application.

Verify that the machine enters the defined safe state (in accordance with the risk analysis) depending on the result of the FB outputs/system variables evaluation.

Use appropriate safety interlocks where personnel and/or equipment hazards exist.

Validate the overall safety function and test the application.

In addition to the use of the corresponding system variables provided by the Safety PLC, the diagnosis of the PROFIsafe/FSoE up-/downstream communication can also be carried out using the following function blocks. These FBs support the display and acknowledgement of PROFIsafe/FSoE diagnostic messages. For details on the FBs (descriptions of the formal parameters and their use), please click on the links.

Available FBs for PROFIsafe diagnostics:

PROFIsafe_F_Addr_Diagnostic: diagnostic of one specific PROFIsafe downstream F-connection
PROFIsafe_F_Global_Diagnostic: global diagnostic of several PROFIsafe downstream F-connections
PROFIsafe_F_Addr_Diagnostic_Upstream: diagnostic of the PROFIsafe upstream F-connection

Available FBs for FSoE diagnostics:

FSoE_F_Addr_Diagnostic: diagnostic of one specific FSoE downstream F-connection
FSoE_F_Global_Diagnostic: global diagnostic of several FSoE downstream F-connections

Term definition: "Downstream" refers to the direction of data flow from the higher-level to the lower-level device. "Upstream" refers to the data flow from the lower-level device to the higher-level device.

For PROFIsafe this means:

Downstream = F-Host >> F-Device
Upstream = F-Device >> F-Host

For FSoE this means:

Downstream = FSoE Master >> FSoE Slave