Index:
------
1.0 IMU Introduction
1.1 IMU Start
1.2 IMU Coarse Align
1.3 IMU Fine Align
1.4 Zero IMU
1.5 Monitor Gimbal Angles
1.6 Monitor PIPA Counter Values
2.0 DAP (Digital Autopilot) Data Initialization
2.1 DAP Activation and Modes
3.0 Show Alarm Codes & Data


1.0 IMU Introduction
--------------------
The IMU is constructed by using a navigational platform gimbaled by a three axis system.
The following mapping is valid after setting the IMU to zero degrees:

X-Gimbal-Axis = Outer Gimbal  = X-LM-Axis = YAW
Y-Gimbal-Axis = Inner Gimbal  = Y-LM-Axis = PITCH
Z-Gimbal-Axis = Middle Gimbal = Z-LM-Axis = Roll (Gimbal Lock +/-70 Degress)

1.1 IMU Start:
--------------
- AGC Crew Inputs: Set "ISS TURN ON REQUESTED" to ON
- Wait for about 90 sec until the DSKY "NO ATT" signal goes off 

1.2 IMU Coarse Align:
---------------------
- Type the following sequence into the DSKY: V41N20E
  V = Verb; N = Noun; E = Enter
- Now the AGC asks for the angles in the format 000.00 Deg
  The sequence is X, Y, Z. Don't forget the "+" or "-"!
- The AGC drives the IMU to the absolute position given
- Use the "FDAI/IMU" window to control the angle changes 

1.3 IMU Fine Align:
-------------------
After IMU Coarse Align the "NO ATT" light indicates that the
platform is not correctly aligned.
To finalize the alignment the following procedure is needed:
- DSKY: V42E
- Give the relative angles in format 00.000 Deg (e.g. 3 x +00000)

1.4 Zero IMU:
-------------
Here are three possible scenarios to reset the IMU to zero degrees:
1.) AGC Crew Inputs: Activate: "IMU CAGE COMMAND TO DRIVE IMU GIMBAL ANGLES TO 0"
2.) DSKY: V40N20E (AGC sends ZERO CAGE COMMAND)
3.) DSKY: V36E (AGC RESET which automatically resets the IMU)

1.5 Monitor Gimbal Angles:
--------------------------
DSKY: V16N20E

1.6 Monitor PIPA Counter Values:
--------------------------------
DSKY: V16N21E


2.0 DAP (Digital Autopilot) Data Initialization:
------------------------------------------------
The DAP needs some initializations values to work correctly (e.g. LM Weight etc.).

- Start Spezial Software Routine R03 => DSKY: V48E
- The Register 1 (F06 46) shows the following value 21122 = ABCDE

Spacecraft Configuration:
A = 1  Ascent Stage Only
A = 2  Ascent and Descent Stage
A = 3  Ascent and Descent Stages docked with CSM

RCS Configuration:
B = 0  2 Jet Translation RCS System A
B = 1  2 Jet Translation RCS System B
B = 2  4 Jet Translation RCS System A
B = 3  4 Jet Translation RCS System B

ACA Scaling:
C = 0  Fine Scaling ACA (4 Deg/Sec)
C = 1  Normal Scaling ACA (20 Deg/Sec)

Deadband Configuration:
D = 0  ATT Deadband 0.3 Degrees
D = 1  ATT Deadband 1.0 Degrees
D = 2  ATT Deadband 5.0 Degrees

KALCMANU RATE:
E = 0  0.2 Deg/Sec
E = 1  0.5 Deg/Sec
E = 2    2 Deg/Sec
E = 3   10 Deg/Sec

- To change the value type V21E
- To proceed press "PRO" to start the entry of (F06 47) LM & CSM Weight
- Use V21E or V22E to change the individual values.
- V24E allows to change both values sequencially (don't forget the leading + sign)
- Proceed with "PRO"
- F06 47 allows the entry of the Engine Gimbal Angles.

2.1 DAP Activation and Modes:
-----------------------------
DAP Activation:
- AGC Crew Inputs => "ATTITUDE HOLD MODE ON" or "AUTO STABILIZATION OF ATTITUDE ON"

DAP Modes:
- DSKY: V76E Minimun Impulse Command Mode (each RHC deflection fires the thrusters for 14ms)
- DSKY: V77E Rate Command and Attitude Hold Mode


3.0 Display Alarm Codes and Data:
---------------------------------
- Alarm Codes => DSKY: V05N09E
- Alarm Data  => DSKY: V05N08E

