What it actually takes to connect a roaster to software

Roasting software is the easy half. The hard half is getting a number off your machine and into a computer, reliably, once a second, for the next ten years. That part is hardware, and nobody selling you software enjoys talking about it.

Here is the whole chain in the order you meet it, so you can work out where your own roaster sits before anyone quotes you.

One: something that senses heat

A thermocouple is two dissimilar metals joined at a tip. Heat the joint and it produces a tiny voltage. Type K is the trade standard for bean temperature because it survives roasting temperatures and costs very little. It is fast, and it is not especially accurate in absolute terms, which matters less than you would think: you are looking for repeatability, not truth.

An RTD is a resistor whose resistance changes predictably with temperature. More accurate, more stable, slower to respond. Good for environmental temperature, poor for catching a turning point.

Probe thickness is the decision people get wrong. A thin probe responds quickly and reads noisily. A thick probe reads smoothly and lags. A 3mm probe will show you first crack arriving; a 6mm probe will show it to you slightly after it happened. Neither is wrong, but you cannot compare curves across two different probes and you should not try.

Two: something that reads the sensor

The voltage off a thermocouple is measured in microvolts. It needs converting and amplifying before a computer can use it. That is what a Phidget, an Arduino board, or your roaster's own controller is doing.

If your machine already has a display showing bean temperature, this stage exists inside it. The question then is not whether the machine can measure, but whether it will tell anyone what it measured.

Three: something that speaks a protocol

This is where machines separate into three groups, and it decides how much work you are in for.

It already speaks Modbus

Most modern production roasters do, over TCP on an ethernet cable or RTU over serial. This is the good case: a network cable and an address, and you are reading. Many will also accept commands back, which is how software can drive gas and air.

It speaks a vendor PLC protocol

Siemens S7 is common on larger machines. Same idea, different dialect, and support depends on the software rather than on you.

It speaks nothing

Older or smaller machines with an analogue gauge, or a display and no port. Here you add your own probes and your own converter, and the machine never knows. This works perfectly well. It is also the case where you are drilling a hole in someone's roaster, so it is worth being sure.

What this means for a specific roastery

If you run a modern production machine from a major manufacturer, you are probably in group one and the job is an afternoon. If you run a sample roaster or something built before ethernet was standard, you are in group three, and the job is a probe kit, a converter and someone comfortable working on the machine.

The middle case, group two, is the one to ask a direct question about before buying anything: does this software support my exact controller, not my manufacturer. Manufacturers ship several controllers across a range and across model years.

RoastConsole Pilot reads Modbus TCP and Siemens S7, along with direct support for common probe hardware, and it runs on the Mac at the machine rather than in a browser. If you are in group three and unsure what you have, send us a photo of the back of the roaster and the controller model plate. We will tell you what it needs, including when the answer is that Artisan already does this for free and you do not need us for it.