M301's "B", "T", "W", and "S" parameters

[Yonkiman]

I read here https://duet3d.com/wiki/Tuning_the_heater_temperature_control that "the B0 parameter tells the system to use PID (the default on power up is bang-bang for the bed heater)." And I've seen this in other config.g files: "M301 H0 P10 I0.1 D200 T0.4 W180 B30 S1.0"

But the wiki (https://duet3d.com/wiki/G-code) only documents H, P, I, and D.

What do B, T, W, and S do?

Cheers,

[Yonkiman]

OK, from M307 docs I can infer that:
"Bn selects Bang-bang control instead of PID if non-zero. Default at power-up is 0 for extruder heaters, 1 for the bed heater." Does that mean that B30 is the same as B1?

"Snnn maximum PWM to be used used with this heater on a scale of 0 to 1. Default 1.0."

I'm getting there…

[Yonkiman]

…and now I just figured out that M301 is deprecated and all I need is M307. So never mind!