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RISER

System blueprint

This page is the map of the whole RISER system — every wire from a sensor in the boiler room to the operator’s browser. It is written for developers and field technicians. If you are pulling wire, start here and on Controller & field wiring. If you are reading code, pair it with From code to copper.

The drawing below is the per-building connection diagram (Sheet 1). It is the same drawing an electrician would work from. A print/PDF-ready version with the full parts list (Sheet 2) is here: open the full blueprint (two sheets, with a Download-PDF button).

The one rule the whole drawing obeys. The controller drives the interposing relay only — it never switches line voltage directly, and it never touches the boiler’s native safety chain (aquastat, low-water cutoff, relief valve). Lose the cloud, the cellular link, or the whole controller, and the boiler falls back to its own controls. The system fails safe to heat.

CELAYA SOLUTIONS EL PASO, TEXAS RISER SYSTEM CONNECTION BLUEPRINT PER-BUILDING FIELD WIRING : SENSOR TO CONTROLLER TO BOILER TO CLOUD SHEET 1 OF 2 : CONNECTION DIAGRAM REV [A] CLOUD & CONNECTIVITY FIELD SENSORS EDGE CONTROLLER ACTUATION, BOILER & NATIVE SAFETY POWER ANT N1 SIM N2 LTE Network CARRIER N3 Internet N4 RISER Backend FastAPI K1 Postgre SQL K2 Operator WEB APP K3 TELEMETRY UP : 15s COMMANDS DOWN : 5s HTTPS Supply Water Temp M12TXSS RTD : 4-20mA S1 Return Water Temp M12TXSS RTD : 4-20mA S2 Steam Pressure DWYER 616KD : 4-20mA S3 STEAM ONLY Outdoor Air Temp RTD XMTR : 4-20mA S4 Flue Gas Temp TEMPCO TPW00036 : TYPE K S5 4-20mA 4-20mA 4-20mA 4-20mA TYPE K ModBerry 500 CM4 C1 RISER EDGE AGENT AI1 supply 4-20mA AI2 return 4-20mA AI3 press 4-20mA AI4 outdoor 4-20mA TC1 flue TYPE K RS-485 A/B/G DO1 relay 24V PWR 24VDC Local control loop : safety interlocks Hardware + software watchdog Store-and-forward buffer (SQLite) Interposing Relay BRIIDEA 24V to 120V R1 Boiler Modbus CTRL (modern) B2 Boiler / Burner EXISTING PLANT UNDER CONTROL B1 Call-for-heat from R1, gated by safety chain NATIVE SAFETY CHAIN : NEVER BYPASSED Aquastat SF1 Low-Water SF2 LWCO Relief Vlv SF3 PRV RELAY DRIVE 24V RS-485 / MODBUS CALL FOR HEAT BURNER ENABLE STRING (SERIES) 120VAC SERVICE P1 24VDC PSU DIN P2 UPS RIDE-THROUGH P3 120V 24VDC 120VAC SWITCHED LINE LEGEND : CONNECTION TYPES 4-20mA analog signal Type K thermocouple RS-485 / Modbus (digital) Relay-switched / call-for-heat 120VAC mains 24VDC power Cellular / RF link Internet / HTTPS TAG KEY S# sensor : C# controller : P# power : R# relay : B# boiler : SF# native safety : N# network : K# cloud Controller drives the interposing relay only. It never switches line voltage directly. System fails safe to heat. Celaya Solutions El Paso, Texas PROJECT RISER Smart Boiler Platform DRAWING Per-Building System Connection PREPARED FOR Rafael Harvey DRAWN BY C. Celaya DATE [date] SCALE NTS REV [A] SHEET 1 OF 2 hello@celayasolutions.com

How to read the drawing

Section titled “How to read the drawing”

The system is drawn in four horizontal bands, left to right = field to cloud:

Band What lives there Who cares
Field sensors RTDs, pressure transmitter, thermocouple (S1–S5) Field tech
Edge controller ModBerry 500 CM4 running the RISER edge agent (C1) Both
Actuation, boiler & native safety Interposing relay, boiler, aquastat / LWCO / relief (R1, B1, B2, SF1–SF3) Field tech
Cloud & connectivity LTE → internet → FastAPI backend, Postgres, operator web app (N1–N4, K1–K3) Developer
Power 120 VAC service → 24 VDC PSU → UPS (P1–P3) Field tech

Wire colors (the legend)

Section titled “Wire colors (the legend)”

Every line on the drawing is a real cable, and its color tells you the signal:

Color / style Signal Notes
Green solid 4–20 mA analog Supply/return/outdoor temp, steam pressure → controller analog inputs
Amber solid Type-K thermocouple Flue gas temp → controller TC1
Blue dashed RS-485 / Modbus Onboard sensor module (internal bus) and the boiler controller (external bus)
Orange heavy Relay-switched / call-for-heat Controller DO1 → relay coil → boiler’s call-for-heat
Red 120 VAC mains Service feed and the switched line through the relay contact
Black 24 VDC power PSU → UPS → controller
Purple dotted Cellular / RF Antenna and SIM up to the LTE carrier
Teal Internet / HTTPS Carrier → internet → backend → web app

Tag key

Section titled “Tag key”

Every box carries a tag. The first letter is its family:

S# sensor · C# controller · P# power · R# relay · B# boiler · SF# native safety · N# network · K# cloud

These same tags key the bill of materials and the code-to-hardware map, so a part on the drawing, a part on the shelf, and a channel in the config all line up.

The path of one heat cycle

Section titled “The path of one heat cycle”

Follow the wires end to end and this is what happens on a normal call for heat:

  1. Sensors read. The supply/return RTDs, the outdoor RTD, and (on steam) the pressure transmitter push 4–20 mA into the controller; the flue thermocouple pushes a Type-K signal.
  2. The agent decides — locally. The edge agent runs its control loop on the ModBerry, checks the interlocks, and decides whether to call for heat. This never waits on the internet.
  3. The relay switches. The agent energizes DO1 → the interposing relay R1 → the boiler’s call-for-heat. The controller drives only the low-voltage coil, never line voltage.
  4. Native safety has the last word. The call passes through the series burner-enable string (SF1 aquastat → SF2 low-water cutoff → SF3 relief). Any one of them can kill firing on its own, independently of RISER.
  5. Telemetry goes up. Every ~15 s the agent posts readings over LTE → internet → the FastAPI backend (K1), which stores them in Postgres (K2). Every ~5 s it polls for commands.
  6. Operators watch. People manage the fleet from the operator web app (K3). See Operator & admin panels.

Cloud loss is not a fault. Cut the antenna, pull the SIM, or unplug the internet, and steps 1–4 keep running on the controller. Telemetry buffers on the controller (SQLite) and drains in order when the link returns — nothing is lost. See The safety rules.