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Installation Guide

How to connect the AutoclaveXpress Trilogy

A complete, field-tested walkthrough for wiring a sterilizer to the cloud — from the PT100 probe in the chamber, through the RS485 converter and the Ethernet gateway, all the way to your live AutoclaveConnectPro dashboard.

Time: about 45–60 minutes Level: Intermediate Tools: screwdriver, ferrules, multimeter

The AutoclaveXpress Trilogy turns almost any autoclave or steam sterilizer into a connected, auditable device — with no PC at the bench and no software to install on site. This guide takes you through every physical connection and every setting, in the order you should do them, so that a first-time installer can finish with cycle data flowing to the dashboard. Read it once end to end before you pick up a screwdriver; the few minutes you spend planning will save you far more in rework.

01How the signal chain works

Before wiring anything, it helps to understand the path a single temperature reading travels. The Trilogy is a short, sealed chain of three devices, each doing one job and handing off to the next. Nothing in the chain needs a computer on site, which is exactly what makes the system easy to retrofit onto sterilizers that were never designed to be connected.

It begins at the PT100 probe, a platinum resistance thermometer whose electrical resistance changes in a precise, repeatable way with temperature. The probe does not output a number; it outputs a resistance, and something has to measure that resistance and turn it into data. That is the job of the Lucid485 converter. It energises the RTD, reads its resistance, compensates for the cable, and publishes the resulting temperature as a digital value on an RS485 bus using the Modbus RTU protocol — the same rugged, long-distance signalling used across industrial and medical equipment for decades.

RS485 is reliable but it is a serial bus, not a network. To reach the cloud, those Modbus readings have to become Ethernet traffic. That is the role of the Waveshare RS485-to-Ethernet gateway: it sits on your local network with its own IP address and transparently bridges the serial bus to TCP/IP, so the cloud can read the converter as if it were on the same wire. From there the data travels over your internet connection to AutoclaveConnectPro, which stores every reading, reconstructs each cycle curve, scores it, and presents it on the dashboard with export-ready records.

Why this matters Because each stage is independent, you can test the chain one link at a time. If something is wrong later, you will know whether it is the probe, the converter, the gateway or the network — rather than staring at a blank dashboard with no idea where to look.

02Safety & what you need

You are working near a pressure vessel that operates at high temperature, and you are making low-voltage electrical connections. Neither is dangerous when treated with respect, but both deserve it.

Read before you start Isolate and power down the sterilizer at the mains before opening any panel. Never drill into, weld onto, or otherwise breach the pressure chamber or its certified fittings — the probe is installed in an existing port or thermowell, never by modifying the vessel. If your sterilizer is under warranty or subject to a validation contract, confirm that adding an external sensor is permitted before you begin. When in doubt, involve your biomedical engineering team.

The Trilogy hardware itself runs on low-voltage DC, so once the sterilizer is isolated the wiring work is comparable to any RS485 instrumentation job. Have the following on hand:

One golden rule Throughout this guide, the device's own printed labels and datasheet are the final authority on terminal names, voltage ranges and default settings. Where this guide gives a typical value, always confirm it against the module in your hand before applying power.

03Step 1 — Mounting and wiring the PT100 probe

The probe is the foundation of every reading, so its placement decides the quality of all your data. Fit the stainless-steel tip where it genuinely represents chamber conditions — ideally in the manufacturer's measurement port or a thermowell, in the position your validation already trusts. Avoid resting it against a cold wall or directly in a steam jet, either of which will bias the curve.

PT100 temperature probe with shielded cable and three spade terminals
The PT100 probe. The two matching-colour leads form the compensation pair; the odd-coloured wire is the third RTD connection.

Routing the cable

Run the shielded cable away from heat sources and away from motors, contactors and mains cables, which radiate electrical noise. Keep gentle bends, secure the cable with the supplied ties, and leave a small service loop near the converter so the wire is never under tension. The shielded braid you can see along the cable is there to reject interference; do not strip it back further than necessary.

Understanding the three wires

This is a 3-wire PT100. The third wire is not a spare — it lets the converter cancel out the resistance of the cable itself, which is essential for accuracy over any meaningful length. Look at the spade terminals: two wires share one colour and one wire is a different colour. The two matching wires are the compensation pair and connect to the two terminals that the converter marks as the paired RTD inputs; the odd-coloured wire connects to the remaining RTD terminal.

Field tip If the colours on your probe are ambiguous, a multimeter settles it instantly: across the two wires of the compensation pair you will read close to zero ohms, while either of those to the third wire reads roughly 110 Ω at room temperature (a PT100 is 100 Ω at 0 °C and rises with temperature).

Do not connect the probe to the converter's RTD terminals yet if it is easier to wire the converter on the bench first — but in most installs it is simplest to land the probe wires now, tighten each terminal firmly onto its ferrule, and give every wire a gentle tug to confirm it is captured. A loose RTD wire is the single most common cause of a jumpy or drifting temperature trace.

04Step 2 — Wiring and configuring the Lucid485 converter

The Lucid485 is the yellow-faced module that turns the probe's resistance into Modbus data. It is built for DIN-rail mounting, so clip it onto the rail first, leaving a little space on either side for the terminal blocks and for airflow.

Lucid485 PT100-to-RS485 converter, DIN-rail module with green terminal blocks
The Lucid485 converter. RTD input on one side, RS485 A/B/GND output on the other, with the POWER and STATE LEDs on the yellow face.
Wiring diagram: PT100 sensor to RS485 converter, showing RED and WHITE leads, power and A/B output
The full wiring at a glance. PT100 leads to the converter's RTD input, 10–30 VDC power, and the RS485 A(+)/B(-) output. Always follow the exact terminal mapping printed on your own module, as shown here.

Power

Connect DC power to the converter's supply terminals, observing polarity exactly as printed on the label — reversing positive and negative is the fastest way to damage a module. Apply power and confirm the POWER LED lights steadily. If it does not, remove power immediately and recheck the polarity and voltage against the label before going further.

The RTD input

Land the 3-wire PT100 on the converter's RTD input terminals as described above: the matched pair to the two paired terminals, the odd wire to the third. The converter's printed legend (often near the IO terminals) shows which is which; follow it rather than guessing. Once wired and powered, a correctly read probe should make the converter report a sensible room temperature when you query it.

Serial settings that must match downstream

The converter speaks Modbus RTU over RS485, and three settings have to agree along the whole bus: the slave (unit) address, the baud rate, and the data format (data bits, parity, stop bits). Note the converter's current values — whether set by DIP switches, by a configuration register, or shipped at a documented default. You do not have to change them; you simply have to record them, because the gateway and the cloud will be told to use exactly the same values.

SettingWhat it isTypical default*
Slave addressThe converter's Modbus unit ID on the bus1
Baud rateSerial speed, in bits per second9600
Data formatData bits / parity / stop bits8-N-1

*Confirm against your module's label and datasheet — defaults vary between firmware revisions.

RS485 output

Finally, identify the converter's RS485 output terminals, usually labelled A, B and GND. These three lines carry the data to the gateway in the next step. Leave them accessible; you will connect them shortly.

What the STATE LED tells you Once the gateway is polling, the converter's STATE LED typically blinks with each Modbus exchange. A STATE LED that never blinks after the gateway is live almost always means the RS485 wiring or the serial settings do not match — a useful clue you will return to in troubleshooting.

05Step 3 — Wiring and configuring the Ethernet gateway

The Waveshare RS485-to-Ethernet gateway is the white module with the RJ45 socket. It is the bridge between the serial world and your network. Mount it on the same DIN rail, close enough to the converter that the RS485 link is short.

Waveshare RS485-to-Ethernet gateway with RJ45 socket and screw terminals
The Waveshare gateway. The RS485 screw terminals bridge to the RJ45 Ethernet socket that puts your cycle data on the network.

Power

Wire DC power to the gateway's supply terminals, again matching the label's voltage and polarity. Many installs power the converter and the gateway from the same supply — perfectly fine, as long as the supply's voltage and current rating suit both modules. Confirm the gateway's power indicator lights when energised.

RS485 wiring

Connect the converter to the gateway terminal-for-terminal: A to A, B to B, and GND to GND. The A/B pair carries the differential signal and the GND provides a common reference; all three matter. RS485 is forgiving of distance but not of crossed A and B lines, which is the classic first-time mistake.

About termination Over the short cable run inside one cabinet, you normally do not need a termination resistor. On long runs, or if you see intermittent data, a 120 Ω resistor across A and B at the far end of the bus stabilises the signal. Add it only if distance or noise calls for it.

The network side

Plug a patch cable from the gateway's RJ45 socket to your switch or router. The gateway now needs an address on your network and needs to know how to talk to the converter. You configure it either through the manufacturer's setup utility (the Waveshare VirCom tool) or through its built-in web page. On a fresh unit the gateway ships with a documented default IP address; put your laptop on the same subnet to reach it the first time, then change the settings to suit your site.

Gateway settingWhat to choose
IP addressA static IP on your LAN (recommended) or a DHCP reservation, so the address never changes.
Serial parametersSet baud rate and data format to exactly match the converter (e.g. 9600, 8-N-1).
Working modeThe mode that exposes the serial device to the network — typically a Modbus TCP ↔ RTU gateway mode, or the transparent/TCP mode specified in your AutoclaveConnectPro provisioning sheet.
Local portThe TCP port your provisioning sheet specifies (commonly 502 for Modbus TCP).
Change the defaults Before this device touches a clinical network, change any default administrator password on the gateway. An unsecured serial-to-Ethernet bridge is exactly the kind of forgotten device that weakens a hospital network. Strong credentials here cost nothing and matter a great deal.

06Step 4 — Network and internet

With the gateway addressed, place it properly on your network. A static IP or a DHCP reservation is strongly preferred: if the gateway's address drifts, the cloud loses the device. Note the final IP address on the install sheet and on a physical label — future-you will be grateful.

The gateway also needs a path to the internet so that AutoclaveConnectPro can reach it, or so it can reach the cloud, depending on the mode in your provisioning sheet. In most clinical networks outbound connections are allowed by default, but tightly managed networks may need a firewall rule. Share the destination host and port from your provisioning sheet with whoever administers the network, and confirm the path is open.

Network itemRecommendation
AddressingStatic IP or DHCP reservation for the gateway.
SegmentationWhere possible, put the device on the network segment your IT team uses for medical equipment.
Outbound pathAllow the gateway to reach the AutoclaveConnectPro host and port listed in your provisioning sheet.
DocumentationRecord the IP, port and physical location for every installed gateway.

07Step 5 — Provisioning AutoclaveConnectPro

The hardware is now ready; the last step is to introduce it to the cloud. Your AutoclaveConnectPro welcome pack contains an activation code and usually a QR code that ties this gateway to your account.

  1. Sign in to your AutoclaveConnectPro workspace.
  2. Choose to add a device and enter the activation code, or scan the QR code from the pack.
  3. Give the device a clear name and map it to the specific sterilizer it monitors — for example "CSSD — Autoclave 2". Good names are what make a multi-site fleet readable later.
  4. Enter the gateway's address and port exactly as you configured them, so the platform knows where to read the converter.
  5. Save. The platform begins polling the converter through the gateway and confirms the link.
Name as you mean to continue If you will eventually run several sterilizers across several sites, settle on a naming convention now — site, room, machine. Consistent names turn a long device list into something you can scan at a glance and audit without guesswork.

08Step 6 — First cycle and verification

Now prove the whole chain end to end. Work through the indicators from the probe outward, then watch a real cycle.

The LED checklist

On the dashboard, the device should show as online and report a plausible idle chamber temperature. If it does, the serial settings, the RS485 wiring, the network path and the cloud mapping are all correct — every link is proven.

Run a cycle

Start a normal sterilization cycle and watch the dashboard. You should see the temperature climb through heat-up, hold across the plateau, and fall during exhaust — the characteristic curve of a real cycle, drawn live. When the cycle ends, confirm that AutoclaveConnectPro has stored a complete record with its curve, timestamps and result, and that you can export it as a PDF. That exported record is the whole point of the system: a load that can stand up to an audit.

Remember what the data is — and is not AutoclaveConnectPro monitors, logs and analyses cycles. It does not replace your biological and chemical indicators, your routine testing, or your validated release procedure. The records are a powerful tool for traceability and early warning; they are not, on their own, the basis for releasing a sterilized load. Your established validation process remains in charge.

09Troubleshooting

Almost every first-install problem falls into a handful of patterns. Work down this table in order — it follows the signal chain from power to cloud.

SymptomLikely causeFix
No POWER LED on a moduleReversed polarity or wrong voltageRemove power; recheck polarity and voltage against the label; re-apply.
Temperature jumps or driftsLoose or mis-paired RTD wireRe-seat all three probe wires; confirm the matched pair is on the paired terminals.
STATE LED never blinksRS485 not communicatingSwap A and B; confirm GND is connected; check baud and format match.
Device offline in dashboardNetwork or address problemPing the gateway; confirm its IP, the TCP port, and that the address has not changed.
Gateway reachable, still no dataSerial parameters mismatchMake the gateway's baud, parity and stop bits identical to the converter's.
Works on the bench, fails on siteFirewall blocking the cloud pathAsk IT to allow the outbound host and port from your provisioning sheet.
Reading offset by a few degreesCable resistance or probe placementConfirm 3-wire (not 2-wire) wiring; check the probe sits where it represents the chamber.

10Maintenance and good practice

A clean install stays reliable for years with very little attention, but a few habits keep it that way.

Need a hand? If anything in this guide does not match the modules in front of you, or a cycle will not appear on the dashboard, our team can walk the chain with you link by link. Reach us at contact@iot.autoclavexpress.com — and have your gateway IP, serial settings and a photo of the wiring ready, as they make remote help far faster.

That is the whole chain: a probe in the chamber, a converter that turns resistance into data, a gateway that puts it on the network, and a cloud that turns it into records you can trust. Once it is running, every cycle is on the record — automatically, on any autoclave or steam sterilizer you choose to connect.