Serial/RS232 Switching only switches one monitor on dual monitor KVM

KVM Model:

MKAG-8KT3124 (HDMI 2.1, 4 PC, 2 Monitor)


Problem:

When switching via serial, using V=1[Enter], V=3[Enter] etc, only the bottom HDMI input/output and the USB are switched, the top HDMI input/output remain on the initial selection.

Other Notes:

I have only started testing the RS232 serial control recently after building a custom cable.

I can connect to the KVM and get a list of commands by entering ?

I can switch inputs by entering commands such as V=1[Enter] or V=3[Enter] or V=>[Enter] and the KVM responds with ">" and a beep.

However, the video port selection using numbers (V=1, V=2, V=3 etc) is only switching one of the monitors. The other monitor remains showing the initial input/computer.

Consider I am using the “top” HDMI ports as “Monitor 1”, and the “bottom” HDMI ports as “Monitor 2”.

For example, if I start on Input 1, using the front panel buttons, Monitor 1 and Monitor 2 are showing the respective displays for Screen 1 of Input 1 and Screen 2 of Input 1.

If I then enter V=3, I get the “top” HDMI inputs remain showing Input 1, whereas the bottom HDMI input correctly switches to Input 3 along with USB. The coloured LEDs on the back of the KVM reflect this too - where the top LED remains on the original colour, and the bottom LED changes. The LED on the front shows green+red as if everything has switched correctly.

If I use the V=> and V=< commands to cycle through active connections, both monitors do switch synced together as expected. But this isn’t necessarily what I want to do, because I want to explicitly choose Input 1, 2, 3, or 4, skipping over Input 2, for example.

The TESmart KVM I tried before settling on the L1Techs KVM supported a mode for split switching like this, but I don’t even see split switching as an option/feature on the L1Techs KVMs so it’s not clear why it’s doing it. Is there some hidden feature that has been turned on accidentally through an undocumented keystroke or serial command I’ve inadvertently sent at some point?

It should be noted that only the RS232 switching is showing this behaviour. Other switching methods such as the front panel, hotkey, or keypad input are switching both monitors together as a pair, as expected.

@wendell this is serial stuff so I’m deferring to you

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Ok I have some info to pass along to you!


Users can use the serial commands listed below to switch HDMI input ports and monitors at MKAG-8KT3124:

9: V=N [Enter] → both the “top” and “bottom” HDMI input/output and the USB switched to HDMI input N.

2: V=N [Enter] → only the “top” HDMI input/output switched to HDMI input N.

V=N [Enter] → only the “bottom” HDMI input/output and the USB switched to HDMI input N.

the N could be 1, 2, 3 or 4.

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Awesome! Thanks @Level1_Amber, that works perfectly.

I’m currently building a little serial control device, so 9:V=n [Enter] is the sequence I will be using to switch equivalent to the other methods, but it’s really nice to know that the top inputs can be switched independently too!

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