So, while in cruise I've been "looking" around the cockpit, and I've noticed this.

I know this isn't simulated, but...what does this do?

https://imgur.com/a/ddVpL

 

Probably help to know where you found it.

37 minutes ago, Robert3512 said:

what does this do?

I think it's related to running various maintenance tests. Someone who is more knowledgeable in that area would have to address the specifics. It's in the manuals, though, if you'd like to run through there. Just search on one of the unique selections and it should pop up.

25 minutes ago, Captain Kevin said:

Probably help to know where you found it.

Back by the TPS reports... 

It's the selector for the data loader. In my days (1990s), it was right next to a floppy drive. So, any time you needed to update software, you'd select which unit was being updated and insert the required floppy. I believe to update the navdata, you'd select FMC-L and insert the floppy (-ies) containing the navdata. Then you'd do the same for FMC-R. This always happened a day or two before the navdata became active. It was then up to the flight crew to select the active data on the CDU at the appropriate time.

This is of course all from memory, which these days is no longer that good. But you get the gist....

Imagine if this was simulated though. Your navdata is outdated as you forgot to update it before the flight (like I always do) , so instead of exiting the sim, updating and restarting the sim, you just go here, select which FMC you want to update and it downloads the latest navdata via navigraph plug in or whatever and it updates while the sim is still running. 

2 hours ago, tcas_climb said:

Imagine if this was simulated though. Your navdata is outdated as you forgot to update it before the flight (like I always do) , so instead of exiting the sim, updating and restarting the sim, you just go here, select which FMC you want to update and it downloads the latest navdata via navigraph plug in or whatever and it updates while the sim is still running. 

sounds a bit like a request 

6 minutes ago, Ephedrin said:

sounds a bit like a request 

Nah, I suspect they don't really like to waste time on things that the flight crew doesn't have to deal with or are not allowed to play with

So what's with all the "INOP" labels? 

On 19/02/2018 at 2:16 PM, Robert3512 said:

So what's with all the "INOP" labels? 

 

Probably for optional systems. I recall our data loader had fewer switch positions (same active functions, but less inop positions). We used to load SATCOM data via a port at cabin door Left 4, but some airlines might have been able to load data via the cockpit data loader.

a bit late to response . yet as all friends have already mentioned , the Knob is for maintenance you can find relative information regarding it's operations in AMM ATA Chapter 34 - Navigation (( If you can get your hands on it ) . to make it short , it is a system get a report of a chosen system's operations and save it on a diskette. The interfaces inside are 2 LRUs and ADL . The ADL can also be accessed via the CMC and give you the options to write the records on the diskette too. if one if the LRUs is using a different version of software , then the Selector knob should be switched accordingly and also another diskette should be used aswell . no need to mention that data can also be uploaded to the selected system's data base from a diskette aswell. You may want to study Aircraft Digital Systems and Computers to check which kind of ARINCs are being used there too.

A bit of info :

The airborne data loader can be used to load software into an LRU that is software data loadable. For some systems the ADL is also used for data download from specified LRUs
The software that is loaded into an LRU is stored on a 3 1/2 inch floppy diskette. More than one diskette may be required to complete the software installation. The software can only be loaded while the airplane is on the ground.
Some systems have more than one LRU that is software data loadable. These LRUs are
independently selected at the data loader control panel.
In most cases, when multiple LRUs must contain the same software the diskettes must be loaded into each LRU.
The ADL can download and record data on diskette for the FMC, CMC or the ACMS. A configuration file on the diskette identifies the LRU. The data download can be done while the airplane is on the ground.
When power is supplied, the ADL does a self-test that automatically tests the correct operation of the internal hardware and software. If the self-test fails, the ADL FAIL indicator comes on.
After the data loader is energized, if a diskette is not installed, the data loader remains in a ready condition. When a diskette is put into the disk drive, the ADL will try to communicate with the LRU set on the data loader selector switch. After four failed tries, the applicable indicator on the ADL comes on and the tries at communication stop.
Remove and put the diskette back into the disk drive to start the communications between the data loader and the applicable LRU again.
Two ARINC 429 data busses are provided to move data between the applicable LRU and the ADL.
Data movement is in one direction only on each bus. The two ways to move data are automatic operation and control operation.
During automatic operation, whole files of data are moved without any additional commands.
Automatic data movement starts when the ADL sends a "REQUEST TO SEND" word, followed by a "CLEAR TO SEND" word from the applicable LRU.
While in control operation, the applicable LRU tells the ADL to do specified disk and data movement operations. This operation starts with a "Request to Send" word from the ADL. The applicable LRU responds with a "Header" word which contains the applicable control commands.
The condition of the data while it moves or the condition of the ADL internal software is shown by the LEDs mounted on the ADL.


I hope This Satisfies your need of answers regarding that knob . also sorry that i can't provide you more info since that might get me fired for spreading Specific technical info on an Airplane which is and can be active in passenger configuration for now and years to come . 


Sincerely.

Edited February 23, 20188 yr by Samany69
correcting Paragraphs.

On 2/18/2018 at 10:03 PM, scandinavian13 said:

Someone who is more knowledgeable in that area would have to address the specifics

i hope i can call my self a bit knowledgeable now with those info i provided  

Could you explain the alphabet soup? LRU? ADL? CMC? 

2 hours ago, Robert3512 said:

Could you explain the alphabet soup? LRU? ADL? CMC? 

LRU : Line Repeatable Unit
ADL : Airborne Data Loader
CMC : Central Maintenance Computer 

1 hour ago, Samany69 said:

LRU : Line Repeatable Unit
ADL : Airborne Data Loader
CMC : Central Maintenance Computer 

Thanks. The only thing that came to mind when I saw CMC was the Command Module Computer on Apollo missions.

1 hour ago, Robert3512 said:

Thanks

no problem at all . Happy to help you out . I love to help people learn thing even small ones. as my own teacher always taught me to teach what i'm taught. you can somehow rely on the information as i gave them to you directly from the official doc yet sometimes a little differences might show up with different aircraft variations and airline orders.

Regards.