<p><code>T</code> is the selected tool, <code>T0</code> is the first hotend tool. If you only have one hotend, <code>T</code> and <code>T0</code> are exactly the same. </p>

<p>Do note that G-codes are described on the <a href="https://reprap.org/wiki/G-code" rel="nofollow noreferrer">G-code wiki page</a>, for <a href="https://reprap.org/wiki/G-code#M105:_Get_Extruder_Temperature" rel="nofollow noreferrer"><code>M105</code></a> you can find:</p>

<blockquote>
  <p>The parameters mean the following:<br>
   - T, T0, ..., Tn - extruder temperature. In a single extruder setup, only T will be reported. Some firmware variants will report no T0 in multi extruder setups - in that case T is to be considered the temperature of the first tool. Otherwise, T should be considered the temperature of the currently selected tool (which will be repeated in one of the Tn entries)<br>
   - B - bed temperature<br>
   - C - chamber temperature<br>
   - @ - Hotend power (Prusa only)
   - B@ - Bed power (Prusa only)<br>
   - P - PINDAv2 actual (Prusa MK2.5/s MK3/s only)<br>
   - A - Ambient actual (Prusa MK3/s only)<br></p>
</blockquote>

CC BY-SA 4.0
2020-02-24T22:52:57.697Z
2020-02-24T22:52:57.697Z
0scar
<p>I've setup OctoPrint with the goal to log temperature data of my hot end. So, I've enable serial logging and examined the serial log file.</p>
<p><strong>The Output for an example line is as follows:</strong></p>
<blockquote>
<p>Send: M105</p>
<p>Recv: ok T:20.7 /50.0 B:20.0 /0.0 T0:20.7 /0.0 @:0 B@:0</p>
</blockquote>
<p><strong>So, from what I understand:</strong></p>
<p>T = Thermistor temp of hot end °C</p>
<p><em>In the example, current temp is 20.7 and target temp is 50.0</em></p>
<p>B = temp of bed °C</p>
<p><em>In the example, current temp is 20.0 and target temp is 0.0</em></p>
<p>But what is T0?</p>
<p>Or the @ and B@?</p>

<octoprint>
In OctoPrint when receiving temperature data (M105) what is T0?
FEA42
# In OctoPrint when receiving temperature data (M105) what is T0?

(Asked by: username_0 on 2020-02-24)

I've setup OctoPrint with the goal to log temperature data of my hot end. So, I've enable serial logging and examined the serial log file.

**The Output for an example line is as follows:**

> Send: M105
>
> Recv: ok T:20.7 /50.0 B:20.0 /0.0 T0:20.7 /0.0 @:0 B@:0

**So, from what I understand:**

T = Thermistor temp of hot end °C

*In the example, current temp is 20.7 and target temp is 50.0*

B = temp of bed °C

*In the example, current temp is 20.0 and target temp is 0.0*

But what is T0?

Or the @ and B@?

**Tags:** octoprint

---

## 1 answers

### Answer by username_1 on 2020-02-24. Score: 1 | Accepted answer

`T` is the selected tool, `T0` is the first hotend tool. If you only have one hotend, `T` and `T0` are exactly the same.

Do note that G-codes are described on the [G-code wiki page](https://reprap.org/wiki/G-code), for [`M105`](https://reprap.org/wiki/G-code#M105:_Get_Extruder_Temperature) you can find:

> The parameters mean the following:  
> - T, T0, ..., Tn - extruder temperature. In a single extruder setup, only T will be reported. Some firmware variants will report no T0 in multi extruder setups - in that case T is to be considered the temperature of the first tool. Otherwise, T should be considered the temperature of the currently selected tool (which will be repeated in one of the Tn entries)  
> - B - bed temperature  
> - C - chamber temperature  
> - @ - Hotend power (Prusa only)
> - B@ - Bed power (Prusa only)  
> - P - PINDAv2 actual (Prusa MK2.5/s MK3/s only)  
> - A - Ambient actual (Prusa MK3/s only)


---

