How it works
Extra channels
Declared channels: an exhaust probe or a TC4's third channel, kept with each roast, drawn, used in alarms and exported to Artisan.
A roaster can send more than bean and environment temperature: an exhaust or inlet probe, a TC4's third and fourth thermocouple, a gas pressure. Those values are shown live but not kept. Declare one as a channel and Roastwarden stores it with each roast, draws it on the scope, the history chart and the PDF roast report, lets an alarm watch it, and exports it to Artisan. On a gas drum the exhaust temperature is often the second most useful curve.
Declaring a channel
Roasters → the roaster → Control → Setup → Channels → Edit, then Add a channel:
| Field | What it is |
|---|---|
| Key | the name the value has in the roaster's readings (t3, exhaust). The editor offers the extra keys the roaster sends right now, or type one |
| Label | what the chart, alarms and Artisan call it, up to 24 characters ("Exhaust") |
| Unit | °C (drawn on the temperature axis, in your display unit), % (on the output axis), or other…: a unit of your own, up to 8 characters (kPa), drawn on a scale of its own |
| Unit, top | for a unit of your own, the top of its scale; left empty (auto), the highest value seen |
Save channels. Up to 8 per roaster, each key once. Nothing is declared by default. A machine added from Artisan's catalogue arrives with its extra curves declared (roasters from Artisan's catalogue). Changing the roaster's kind keeps its channels. Temperatures are kept in °C: a probe that reads °F is converted by the mapping, not declared in °F.
Getting the value into the readings. A key must be one the roaster sends and not one of
Roastwarden's own fields (BT, ET, heater, fan, setpoint, drum, damper…). A device on
Roastwarden's own names just adds the field to its JSON; any other device names it in its
mapping, as an extra name for a JSON field, a TC4 column or a Phidgets input, or a Modbus
register with no role, by its name (mapping a device's own names). For
example roast roaster map <roaster> --column ambient,et,bt,heater,fan,exhaust reads a TC4's
sixth column as exhaust.
Where a channel shows
- Scope and history: a dashed line per channel, with a legend entry that hides and shows it. The hover readout does not list channel values.
- PDF roast report: a °C channel is a line on the chart; a % channel or one of your own unit joins the heater and fan strip.
- Alarms: Settings → Alarms, condition Channel above or Channel below, the threshold in the channel's unit. A rule naming a channel no roaster declares never fires, and the editor says so.
- Artisan export: the
.aloggets one Artisan extra device per pair of channels. With no channel declared it has no extra devices, so loading it leaves your Artisan setup alone. Importing an.alogdoes not read its extra devices. - A roast keeps the channels it started with: declaring or removing one later does not change how earlier roasts are drawn or exported.
From the command line, roast roaster show <roaster> lists the declared channels and
roast review <roast> prints each channel's value at CHARGE, first crack and DROP. Declaring
channels is in the dashboard only.