verified connector library

Carel ir33+ refrigeration controller family

Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based as on the wire. Word order and scaling are confirmed at the hardware-verified rung and at no rung below it.

interop-verified

Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.

pointaddress (0-based)typescaleunit
defrost_probe_1_reading0I160.1
defrost_probe_2_reading1I160.1
virtual_probe2I160.1
probe_1_reading3I160.1
probe_2_reading4I160.1
probe_3_reading5I160.1
probe_4_reading6I160.1
set_point15I160.1
max_temperature_read20I160.1
min_temperature_read21I160.1
low_temperature_alarm_threshold26I160.1
high_temperature_alarm_threshold27I160.1
high_condenser_temperature_alarm_threshold28I160.1
frost_protection_alarm_threshold35I160.1

link settings as documented (unverified): Automatic recognition of the network protocol: Carel or Modbus. Supports up to 207 units on the network with a maximum length of 1000 m. Serial address is assigned via parameter H0.

⚠ Separate probe and digital input signal cables from cables carrying inductive loads and power cables. Never run power and signal cables in the same conduits. — Starkest reads only; we never write a control register.

bench facts as documented (unverified)
terminalsfixed screw, plug-in or spade terminals
A/B polarityModel IROPZ485S0 automatically recognises TxRx+ and TxRx- signals (reverse connection)
termination120 Ohm terminating resistor to be installed on the terminals of the last connected controller
connector4 pin AMP connector for programming key / serial interface
isolationreinforced, 6 mm clearance, 8 mm creepage, 3750V insulation from extra low voltage parts
shield/groundconnect only one end of the shield to the earth on the electrical panel
wiring notesRS485 serial interface (P/N IROPZ48500 or IROPZ485S0) plugs directly into the programming key connector
protocol notesMaximum of 207 units on the supervisor network
power12 V~, 12 to 24 V~, 115 V~, 115/230 V~, 230 V~ (50/60 Hz), 12/18 Vdc, 12/30 Vdc depending on model
environmentOperating temperature: -10 to 60 °C (ir33+) or -10 to 65 °C (wide/easy models); Storage temperature: -20 to 70 °C; Humidity: < 90% RH non-condensing; Front panel IP65
accuracyStandard Carel NTC: 1 °C (-50 to 50 °C), 3 °C (50 to 90 °C); High temp NTC: 1.5 °C (-20 to 115 °C); Standard Carel PTC: 2 °C (-50 to 50 °C)
certificationsISO 9001, CE, UL, VDE, EN 13485
doc revisionir33plus +0300028EN rel. 1.1 - 05.05.2017

⚠ disputed: defrost_probe_1_reading @ 0 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which shows no Modbus variables at addresses 0 and 1; analogue variables start at address 3 (Virtual probe).

⚠ disputed: defrost_probe_2_reading @ 1 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which shows no Modbus variables at addresses 0 and 1; analogue variables start at address 3 (Virtual probe).

⚠ disputed: max_temperature_read @ 20 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which maps rH (Maximum temperature read) to Modbus address 22 (0-based: 21).

⚠ disputed: min_temperature_read @ 21 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which maps rL (Minimum temperature read) to Modbus address 21 (0-based: 20).

⚠ disputed: low_temperature_alarm_threshold @ 26 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which maps AL (Low temperature alarm threshold) to Modbus address 28 (0-based: 27). Address 26 is A0 (Alarm differential).

⚠ disputed: high_temperature_alarm_threshold @ 27 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which maps AH (High temperature alarm threshold) to Modbus address 29 (0-based: 28). Address 27 is A1 (Alarm threshold type).

⚠ disputed: high_condenser_temperature_alarm_threshold @ 28 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which maps Ac (Condenser high temperature alarm threshold) to Modbus address 160 (0-based: 159). Address 28 is AL (Low temperature alarm threshold).

⚠ disputed: frost_protection_alarm_threshold @ 35 — disputed by Carel ir33+ User Manual (+0300028EN rel. 1.1) which maps ALF (Antifreeze alarm threshold) to Modbus address 435 (0-based: 434). Address 35 is c8 (Compressor start delay after opening PD valve).

field reports — community-sourced, unverified (checked 2026-06-11)
  • The Modbus serial parameters are fixed to 2 stop bits, no parity, and 19200 baud rate. Many Modbus masters default to 1 stop bit when parity is disabled, which causes communication failures unless explicitly configured to use 2 stop bits. [source]
  • confirmed: Automatic recognition of the network protocol: Carel or Modbus. Supports up to 207 units on the network with a maximum length of 1000 m. Serial address is assigned via parameter H0. — confirmed by Carel ir33+ User Manual (+0300028EN rel. 1.1)
  • confirmed: Operating temperature: -10 to 60 °C (ir33+) or -10 to 65 °C (wide/easy models); Storage temperature: -20 to 70 °C; Humidity: < 90% RH non-condensing; Front panel IP65 — confirmed by Carel ir33+ User Manual (+0300028EN rel. 1.1)
  • confirmed: Model IROPZ485S0 automatically recognises TxRx+ and TxRx- signals (reverse connection) — confirmed by Carel ir33+ User Manual (+0300028EN rel. 1.1)
  • confirmed: 120 Ohm terminating resistor to be installed on the terminals of the last connected controller — confirmed by Carel ir33+ User Manual (+0300028EN rel. 1.1)
  • confirmed: 12 V~, 12 to 24 V~, 115 V~, 115/230 V~, 230 V~ (50/60 Hz), 12/18 Vdc, 12/30 Vdc depending on model — confirmed by Carel ir33+ User Manual (+0300028EN rel. 1.1)

The trust ladder

Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.

If your device isn't here, upload its register map. Generation is free, and the connector keeps the rung it earns under testing.

To prove a connector against your own device, order hardware verification. If it doesn't verify, you don't pay.

Platform builders can license the verified library: machine-readable maps, the firmware matrix, API access.