FSOE Qualifying Test study plan
FSOE Qualifying Test · Give each week a clear focus.
8 weeks · About 8 hours per week
Safety over EtherCAT architecture: black-channel principle, FSoE master/slave roles, safety stack placement in the device
Explain the black-channel principle in your own words, including why FSoE can tolerate non-safe EtherCAT networks and what the safety stack must still verify independently.
Map the FSoE master and slave roles: which node originates safe outputs, which consumes safe inputs, and where each safety stack sits in the device architecture.
Trace a safe input from a sensor terminal through the local safety stack, the FSoE PDU, the standard EtherCAT frame, and back to the master's safety application.
Distinguish FSoE safety data from standard EtherCAT process data by listing what the standard network may and may not do with FSoE payloads.
Your checkpoint
One-page hand-drawn architecture diagram showing FSoE master, two slaves, safety-stack placement in each device, and the safe/standard data boundary, annotated from memory without notes.
Functional safety fundamentals and standards context (IEC 61508, IEC 61784-3, IEC 62061 / ISO 13849 relationship) & Safety over EtherCAT architecture: black-channel principle, FSoE master/slave roles, safety stack placement in the device
Compare the scope and applicability of IEC 61508, IEC 61784-3, IEC 62061 and ISO 13849-1, and state which one governs a given claim such as a SIL 3 safety function or a PL e machine.
Explain how IEC 61784-3 treats FSoE as a functional-safety communication profile built on the black-channel model.
Relate SIL (PFH/PFDavg ranges) to PL (category, MTTFd, DC, CCF) and identify where the two scales are not directly interchangeable.
Identify the safety-lifecycle phases in IEC 61508 and mark which phases FSoE integration evidence belongs to.
Your checkpoint
Four-row comparison table covering standard, scope, quantitative metric and typical FSoE use, plus a written justification of one SIL-to-PL mapping decision.
FSoE frame structure and data coding: safe data container, command field, cyclic redundancy check, connection identifier
Draw the FSoE PDU field by field: command field, safe data container, CRC and related control information, and state the function of each field.
Explain how the connection identifier and FSoE address are checked at reception to reject frames from the wrong connection or the wrong slave.
Distinguish the FSoE command types used for session, connection, parameter and data exchange, and state what changes in the payload for each.
Describe how the cyclic redundancy check protects the safe data container and what a CRC mismatch must trigger in the receiver.
Your checkpoint
Annotated frame map with field names, bit widths and a worked example showing one valid frame and one deliberately corrupted frame with the expected receiver reaction.
FSoE state machine and communication phases: session, connection, parameter and data exchange, fail-safe reaction
Sequence the FSoE communication phases from session through connection, parameter and data exchange to the fail-safe state, and name the command expected in each phase.
Build a transition table listing at least ten transitions with the triggering event, the next state and the receiver's response.
Predict the slave behaviour when the watchdog expires, when an unexpected command arrives, and when the master stops sending data frames.
Distinguish a controlled fail-safe reaction from a communication reset and explain when each is required.
Your checkpoint
Closed-book state transition table with at least ten transitions and a written prediction of device behaviour for three fault scenarios.
Error detection and residual-error measures: sequence monitoring, timeouts, watchdogs, addressing checks, data integrity & FSoE frame structure and data coding: safe data container, command field, cyclic redundancy check, connection identifier
Enumerate the residual-error measures used by FSoE: sequence monitoring, timeout and watchdog supervision, connection and address checking, CRC and data-integrity checks.
Match each measure to the fault class it detects, such as lost frames, duplicated frames, delayed frames, masquerading frames and corrupted data.
Explain how sequence numbers detect repetition, loss and reordering, and why a timeout alone is insufficient.
Estimate qualitatively how the measures combine to reduce residual error probability and identify which single measure is easiest to defeat by misconfiguration.
Your checkpoint
Fault-to-measure matrix covering at least eight fault types, with the detecting measure, the expected reaction time and the residual gap left uncovered.
FSoE configuration parameters: FSoE address, watchdog time, slave-to-slave communication, mapping of safe inputs and outputs & Error detection and residual-error measures: sequence monitoring, timeouts, watchdogs, addressing checks, data integrity
Assign FSoE addresses and watchdog times to a multi-slave network and justify each value against cycle time and fail-safe response requirements.
Describe the constraints and risks of slave-to-slave communication, including which node owns the safety function and how addressing checks still apply.
Map safe inputs and outputs to FSoE data-container positions and verify that the mapping is consistent between master and slave configuration.
Identify configuration errors that pass commissioning but silently disable an error-detection measure.
Your checkpoint
Configuration sheet for a three-slave network with FSoE addresses, watchdog times, I/O mapping table and a list of five configuration traps with their symptoms.
Diagnostics, fault tracing and conformance testing of FSoE devices and networks
Read FSoE diagnostic codes and status information and translate them into the phase or check that failed.
Trace a reported fault from log entry to root cause across master configuration, slave configuration, wiring and network timing.
List the conformance test areas for an FSoE device, including state-machine behaviour, error reactions, timing and frame handling.
Distinguish a device defect from an integration or configuration error using diagnostic evidence.
Your checkpoint
Troubleshooting decision tree plus five worked fault scenarios, each with symptom, diagnostic evidence, root cause and corrective action.
Integration, verification and validation: risk assessment inputs, SIL/PL verification, proof tests, documentation & Functional safety fundamentals and standards context (IEC 61508, IEC 61784-3, IEC 62061 / ISO 13849 relationship)
Derive safety requirements and required SIL/PL from a risk assessment input and allocate them to an FSoE-based safety function.
Verify a sample architecture against its SIL/PL target using PFHd or PL parameters and state the assumptions behind the calculation.
Define proof-test intervals and diagnostic coverage assumptions for the sample function and show how they affect the achieved integrity.
Assemble a documentation package covering configuration, verification evidence, test results and residual-risk notes.
Your checkpoint
Mini safety case for one FSoE safety function: requirements, architecture, verification calculation, proof-test plan and documentation checklist.
Milestones
Week 2: Explain from memory, without notes, where IEC 61784-3 sits relative to IEC 61508 and ISO 13849-1 and correctly classify five given safety claims by governing standard.
Week 4: Reconstruct the full FSoE state sequence and at least ten transitions from memory, and correctly predict the fail-safe reaction for watchdog expiry and unexpected command.
Week 6: Produce correct FSoE addresses, watchdog times and I/O mapping for a three-slave network and justify each value against cycle time and response-time requirements.
Week 8: Complete the mini safety case end to end and score at least 80 percent on a mixed practice set spanning all eight domains, with any weak domain flagged for review.