Gauge calibration of FW- and AFT-OVHT

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Skycowboy
Posts: 54
Joined: Wed Jul 20, 2022 3:20 pm

Gauge calibration of FW- and AFT-OVHT

Post by Skycowboy »

Hej.

the gauges of my AFT- and FW-OVHT of PM 737/738 are don't synchronized with PMDG of MSFS2020.
Are there a possibillity to calibrate it exactly in order to get it synchonized with PMDG.
The reason is, I'm a member in a flight simulator club and I take part to an elaborated and long course of a real pilot to get a type rating for a B-738
(simulating). Therefore it would be importand, that the values of the gauges are reliable.

Best regards
Rolf
mvr1918
Site Admin
Posts: 1704
Joined: Thu Aug 30, 2012 3:35 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by mvr1918 »

yes, it is possible by modify the script you are using.

1) you need to read and understand how a specific gauge script is working

2) you need to find the servo values for main gauge position marks with SIOC's SIOC monitor

3) you need to change the values in the script with the values you found in 2)

This is not complicated as long as you understand how the script for gauges are working.

The default script that comes with the PMDG 737 driver works mostly OK, but as there are variations between all modules due to different alignment of servo arm etc., a calibration is needed to match the virtual values with the hardware values.

The script code can also be improved to get even better results.

The key is to understand how to make a script, how to read servo position values and how the servo works.

Example of document servo arm values to be used in a modified script. You must find your values and use them as described above.
Screenshot 2022-10-06 111831.jpg
Screenshot 2022-10-06 111831.jpg (153.52 KiB) Viewed 2558 times
Skycowboy
Posts: 54
Joined: Wed Jul 20, 2022 3:20 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by Skycowboy »

Hej,

thank you for example and good news!

Best regards
Rolf
Skycowboy
Posts: 54
Joined: Wed Jul 20, 2022 3:20 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by Skycowboy »

Hej,

I changed the range of the EGT gauge and 10 values in relation to the values of SIOC monitor. Now the gauge indicator is exactly synchronized to PMDG gauge! But a stupid question: If I start the MSFS2020/PMDG738 with APU off the indicator of the EGT gauge in PMDG738 is pointing to zero - that's right, but my OC gauge indicator is pointing to 4. (If I start the APU, the OC EGT indicator is initially switching in the direction of zero and increased then synchronized). Which term/value in the script set it initially to zero, too?

Best regards
Rolf
Skycowboy
Posts: 54
Joined: Wed Jul 20, 2022 3:20 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by Skycowboy »

Ok, sorry!
I found the solution in the meantime by myself!

Best regards
Rolf
mvr1918
Site Admin
Posts: 1704
Joined: Thu Aug 30, 2012 3:35 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by mvr1918 »

?? Maybe a good idea to share you solution so other can see it.
Skycowboy
Posts: 54
Joined: Wed Jul 20, 2022 3:20 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by Skycowboy »

Hej,

yes, gladly!

Calibrierung Gauges FW-OVHT - USBServosPlusV1 Dev=74

Values for the individual positions of EGT by SIOC Monitor determined.
EGT: 127(0)-206(1)-269(2)-336(3)-396(4)-454(5)-527(6)-584(7)-642(8)-687(9)-763(10)

Var 0141, name SERVO_EGT, Link USB_SERVOS, Device 37, Output 2, PosL 10, PosC 511, PosR 1000, Type 1 – Line 2546 ----->

Var 0141, name SERVO_EGT, Link USB_SERVOS, Device 37, Output 2, PosL 103, PosC 330, PosR 763, Type 1 – Line 2546

{
L0 = &g_egt
L2 = L0
C0 = L0 >= 0
C1 = L0 <= 100
IF C0 AND C1
{
&g_egt_low_val = 0
&g_egt_high_val = 100
&egt_high_val = 0
&egt_low_val = 224 → 206
}
C0 = L0 >= 100
C1 = L0 <= 200
IF C0 AND C1
{
&g_egt_low_val = 100
&g_egt_high_val = 200
&egt_high_val = 224 → 206
&egt_low_val = 291 → 269
}
C0 = L0 >= 200
C1 = L0 <= 300
IF C0 AND C1
{
&g_egt_low_val = 200
&g_egt_high_val = 300
&egt_high_val = 291 → 269
&egt_low_val = 366 → 336
}
C0 = L0 >= 300
C1 = L0 <= 400
IF C0 AND C1
{
&g_egt_low_val = 300
&g_egt_high_val = 400
&egt_high_val = 366
&egt_low_val = 445 → 396
}
C0 = L0 >= 400
C1 = L0 <= 500
IF C0 AND C1
{
&g_egt_low_val = 400
&g_egt_high_val = 500
&egt_high_val = 445 → 396
&egt_low_val = 521 → 454
}
C0 = L0 >= 500
C1 = L0 <= 600
IF C0 AND C1
{
&g_egt_low_val = 500
&g_egt_high_val = 600
&egt_high_val = 521 → 454
&egt_low_val = 584 → 527
}
C0 = L0 >= 600
C1 = L0 <= 700
IF C0 AND C1
{
&g_egt_low_val = 600
&g_egt_high_val = 700
&egt_high_val = 584 → 527
&egt_low_val = 636 → 584
}
C0 = L0 >= 700
C1 = L0 <= 800
IF C0 AND C1
{
&g_egt_low_val = 700
&g_egt_high_val = 800
&egt_high_val = 636 → 584
&egt_low_val = 681 → 642
}
C0 = L0 >= 800
C1 = L0 <= 900
IF C0 AND C1
{
&g_egt_low_val = 800
&g_egt_high_val = 900
&egt_high_val = 681 → 642
&egt_low_val = 757 → 687
}
C0 = L0 >= 900
C1 = L0 <= 1000
IF C0 AND C1
{
&g_egt_low_val = 900
&g_egt_high_val = 1000
&egt_high_val = 757 → 687
&egt_low_val = 809 → 763
}

With this new values the EGT Gauge is working exactly synchronized with PMDG!!

Zero point OC Gauge EGT after start of Sim: With SIOC Console value find and insert into Script.
Var 1108, name g_EGT, static, Value 0 ---> 70

Best regards
Rolf
mvr1918
Site Admin
Posts: 1704
Joined: Thu Aug 30, 2012 3:35 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by mvr1918 »

Thanks for sharing.
PH-JRJ
Posts: 70
Joined: Fri Jul 07, 2017 6:58 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by PH-JRJ »

Hi Roar,

Why is the script for all servo’s changed? Is this more accurate to than the scriptcode used in OC4BAv5?

Br Remco
mvr1918
Site Admin
Posts: 1704
Joined: Thu Aug 30, 2012 3:35 pm

Re: Gauge calibration of FW- and AFT-OVHT

Post by mvr1918 »

Some small fixes and more accurate gauge outsputs are the main changes.
To find the changes the most easy way it to get Notepad++ and its Compare plug-in and load the scripts and make a compare. Then you will have a very visual understanding of what has changed.
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