need track replay SMS available in A/A, but off in MRM & DGFT override

[Aquorys]

This happened when I started up while on ground power. I had most of the systems on, then started the engine, disconnected the ground power and performed an INS stored heading alignment. Everything seemed normal so far. I took off, then tried to configure my DGFT and MRM override modes. The DGFT override mode just said "SMS OFF" on my MFD, but the MRM override mode worked normally. I toggled ST STA off, then on again, in NAV, then in DGFT override, and when I finally did that in MRM override, it got stuck in "SMS OFF" too. When I switched to A/A mode, it worked normally though.

I landed, shut down the jet, restarted without ground power and the problem was resolved.

However, that does not seem like a plausible malfunction to me, so I believe it is an implementation bug in DCS - or probably rather a design bug. It would make sense for the SMS to be either on or off, regardless of which mode is trying to access it.

I guess for the simulation, that means you want something like a single

bool sms_available

somewhere, and not some 5 independent copies of it, so bugs like this one could not possibly happen.

I will try to reproduce this same problem and possible solutions in single player and report in this thread what I found out.

PS: Do we have an F-16 avionics specialist in here who knows enough details about the hardware and software design to comment on whether the SMS could ever show up as on/available in one mode and as off in another mode at the same time in the real aircraft?

[FusRoPotato]

Yeah I've run into weird SMS issues before while switching between A2A and DGFT. Unfortunately, a track file can't replicate the problem. This probably means that, whatever the bug is, it goes deeper than everything recorded in a track.

Some of the stuff I've seen is akin to:

1. Switch to DGFT
2. Switch to AIM120
3. Switch to A2A
4. Lock target
5. Switch back to DGFT

At this point, the AIM9x tone is heard, but locking a target shows AIM120 ranging launch bars on the hud. It also shows AIM120 selected in the SMS, but fox3 that sucker off and watch an aim9x fly away dumb. I've seen this happen 4-5 times now but a track file shows everything as AIM9x and I think it's supposed to do that, but the SMS and HUD seem to miss out on that update in rare cases only in the moment it happens. In one instance, I caught it in the act and tried to switch weapon before firing. The AIM9x tone went away, but the hud and SMS page stayed on AIM120. I was then able to fox3. So long as you know that DGFT will always switch to fox 2's when entered, it can be easily worked around, but it is confusing at first when the HUD and SMS don't update.

The only way to capture it is to always have video recording tied to a track file, but neither are going to help find a problem like that any better than a basic description. All it will do is validate I'm not crazy.

I suspect something is blocking or corrupting the update because they are supposed to change when switching modes. It may be completely related to your SMS off experience.

Edited July 6, 2022 by FusRoPotato

[Aquorys]

This bug or a possibly closely related bug is reproducible with the following sequence

• Select MRM override or DGFT override mode
• Select ST STA OFF
• Exit MRM override or DGFT override mode
• Select ST STA ON

The SMS page will now show OFF in the mode that was selected when ST STA was turned off, but not the other modes, unless the same procedure was applied. The A/A mode is not affected.

Power cycling the mission computer resolves the problem.

I suspect that similar behavior is triggered when the aircraft is shut down on ground power, and most systems, but not the mission computer, are turned off, and the aircraft is later started up again for another flight. The result seems to be that both, the MRM override and DGFT override modes end up with a non-functional SMS. When I last encountered this problem, power cycling the mission computer also resolved the problem when it was caused during shutdown on ground power.