Lesson 2.1

Trace, classify, hand off

The heritage skill: PPCL — line-numbered structured text on Apogee-era gear. Read it like a programmer: search the point's writes, read surrounding logic — output-backwards in text form (401's law without the pictures).
PPCL LOOP/PID statements are your loops: gains, setpoints, outputs in text syntax; 401's trend shapes still diagnose them.
Modern Desigo engineering returns to block/graphical programming — the 401 vocabulary again.
Priorities on modern BACnet points behave per the standard array (306).
Uncertified but professional: navigate, trend, trace text or blocks, classify (303), hand off — P1-era program changes are certified-tech territory and often an LP retrofit conversation.

Service boundary: PPCL edits and Desigo engineering belong with certified techs — your value is the evidence-rich trace (line numbers cited!) and the clean handoff.

LAB — the mixed-building drill

Identification: from the evidence pack (photos, screens, board labels), identify the Siemens generation and architecture present.
Navigation: on the demo/simulated front end, locate a given point, its trend, its schedule, and its override state within a time box.
Reading: trace one supplied program excerpt against its sequence (expected/observed/delta per 303) and classify the seeded deviation: equipment vs programming vs design.
Handoff: write the service note a Siemens-certified tech could act on immediately.

Pass: identification correct; navigation within the box; deviation classified with reasoning; handoff note professional.

LAB DEMO VIDEO

Instructor walkthrough — navigating the Siemens front end + one trace

[ ~12 min ]

The Siemens two-era map — split architecture: Desigo era (CC → PXC → BACnet field) beside Apogee era (P1/FLN trunk → TEC boxes); PPCL text-excerpt inset vs block-tool inset; era-recognition badges