BAS-503 Visual Aid Library
Figure-use rule
Each figure is an orientation and reasoning aid, not a project drawing. Learners must pair it with the current sequence, point list, wiring/piping documents, manufacturer instructions, and as-found evidence.
Normal-rule anchor
Brand familiarity does not replace architecture: identify where logic executes, where values originate, which interface commands, and which service stores evidence.
Case overlay
A project uses an ECLYPSE controller, ECB terminals, Allure sensors, embedded ENVYSION, and EC-Net supervision, but ownership of schedules and alarms is unclear.
Calculation/evidence callout: Count controllers, networks, supervisory services, protocol paths, execution locations, dependencies, and unresolved authorities.
Normal-rule anchor
Similar-looking controllers are not interchangeable; supported tool/firmware pairing, resource limits, electrical ratings, licenses, and current product instructions govern.
Case overlay
A replacement controller has enough terminals but lacks the required protocol option and does not support the existing room-device path.
Calculation/evidence callout: Reconcile physical and network I/O, program/resource load, protocol/device limits, spare capacity, license count, and support horizon.
Normal-rule anchor
A correct block diagram still fails when data type, initialization, execution order, persistence, or hidden interface assumptions are wrong.
Case overlay
A fan latch returns after restart and a one-cycle pulse is consumed before an alarm block sees it.
Calculation/evidence callout: Build truth/state tables, trace values over several cycles, calculate timer behavior and execution margin, and compare expected to observed watch values.
Normal-rule anchor
Universal terminals require explicit configuration; program value, object value, electrical output, proof, and process response remain separate claims.
Case overlay
A 0-10 V pressure sensor is configured to the wrong range while a higher BACnet priority holds the fan enable off.
Calculation/evidence callout: Calculate slope/intercept, endpoints/midpoint, loop and voltage plausibility, priority result, deviation, and proof timeout.
Normal-rule anchor
A platform library accelerates work but never overrides the actual equipment, approved sequence, airflow/plant constraints, life-safety interfaces, or manufacturer limits.
Case overlay
A single-source rooftop system serves hybrid VVT zones with aftermarket crossflow airflow pickups and requires pressure-aware zone control without pretending it is a central VAV plant.
Calculation/evidence callout: Calculate airflow/setpoint scaling, loop error, reset slopes, stage thresholds, timing, diversity/request counts, and acceptance bands.
Normal-rule anchor
A device discovered on a screen is not commissioned until unique identity, route, object meaning, timing/load, security, physical effect, and as-built record agree.
Case overlay
Two devices share an instance, an MS/TP segment has intermittent token loss, and an imported Modbus value uses the wrong word order.
Calculation/evidence callout: Reconcile subnet and BACnet identities, token/poll timing, register decoding, network load, latency, and before/after error counts.
Normal-rule anchor
Room display state must not imply controller acceptance or equipment proof; local choices require range, authority, timeout, feedback, and fallback.
Case overlay
An occupant changes setpoint and fan mode, but the controller rejects one value and a failed humidity sensor remains displayed as normal.
Calculation/evidence callout: Calculate calibration offset, setpoint bounds, occupancy timeout, update/freshness, failed-sensor fallback, and command-to-acknowledgement time.
Normal-rule anchor
Operator presentation is correct only when context, units, status, freshness, permission, command, proof, failure, and audit behavior are tested together.
Case overlay
A graphic shows a green fan after command despite no proof, and a schedule edit succeeds locally but is overwritten upstream.
Calculation/evidence callout: Measure top-task steps/time/errors, state coverage, history interval adequacy, alarm latency, schedule precedence, and permission outcomes.
Normal-rule anchor
Download success is not release evidence; source, generated project, controller-resident state, parameters, graphics, and backup must reconcile after normal/fault/restart tests.
Case overlay
A copied fan-coil template uses an old point range and the controller upload does not match the project believed to be current.
Calculation/evidence callout: Count changed items and exceptions, compare checksums/versions, calculate download/test duration, regression pass rate, and rollback readiness.
Normal-rule anchor
Remote access uses a named account, least privilege, approved target/actions, time limit, logging, impact control, and verified logout/restoration; it never creates silent production authority.
Case overlay
A remote lab session remains connected after a download and one local override is still active when the student begins handoff.
Calculation/evidence callout: Reconcile test pass/fail/retest, user/permission exceptions, session duration, temporary states, RPO/RTO, and artifact completeness.