Inaccuracy of PID values in the object model

wschadow

When doing a PID tuning and saving the values with M500 P31 the config-override.g hat the following numbers:

.

In the object model the exponent of the cooling rate curve and the dead time are rounded to one digit

It is not only displayed as rounded number, but also the numbers are set to E=1.4, and D=5.7 respectively. This can be seen by the following code

var rnozzle = heat.heaters[1].model.heatingRate
var k1nozzle = heat.heaters[1].model.coolingRate
var k2nozzle = heat.heaters[1].model.fanCoolingRate
var dnozzle = heat.heaters[1].model.deadTime
var enozzle = heat.heaters[1].model.coolingExp
var vnozzle = heat.heaters[1].model.standardVoltage
;
echo >"0:/settings/Set-PID-nozzle.g" "M307 H0 R"^{var.rnozzle}^" K"^{var.k1nozzle}^":"^{var.k2nozzle}^" D"^{var.dnozzle}^" E"^{var.enozzle}^" S1.00 B0 V"^{var.vnozzle}^"  ;  set PID parameters nozzle"

results in

M307 H0 R2.849 K0.645:0.000 D5.7 E1.4 S1.00 B0 V24.1  ;  set PID parameters nozzle

This was tested with Duet2 and Duet3Mini5+ running fw 3.5.0 Release Candidate 1.

wschadow

It looks like an issue with numerics. I just cam across another post [(https://forum.duet3d.com/topic/33677/round-variable-to-nth-digit/2)] and gave this code a try

var rnozzle = heat.heaters[1].model.heatingRate
var k1nozzle = heat.heaters[1].model.coolingRate
var k2nozzle = heat.heaters[1].model.fanCoolingRate
var dnozzle = (10.0* heat.heaters[1].model.deadTime) / 10.0
var enozzle = (10.0* heat.heaters[1].model.coolingExp) / 10.0
var vnozzle = heat.heaters[1].model.standardVoltage
;
echo >"0:/sys/Set-PID-nozzle.g" "M307 H0 R"^{var.rnozzle}^" K"^{var.k1nozzle}^":"^{var.k2nozzle}^" D"^{var.dnozzle}^" E"^{var.enozzle}^" S1.00 B0 V"^{var.vnozzle}^"  ;  set PID parameters nozzle"

The output is