KVM switching.

We have a Congo Senior and a Congo Junior connected as a server and backup pair in our live studio environment - as recommended by ETC. This generally works ok.

However, when we switch between the 2 desks we need to switch our single keyboard and mouse between them - this is performed via a KVM switcher. We find, more often than not, that the KVM switcher 'locks up' and loses all functionality when we switch between the 2 desks. Only a power down/reset of the KVM switcher restores normal operation. We understand that the Senior uses USB 2.0, and that the Junior uses USB 1.1.

We wonder if this is the cause of our problem - that the KVM switcher is not 'happy' with sourcing signals to two different USB spec devices.

Has anyone else experienced these problems - we have tried two diffrent KVM switches and the result is the same - locks up. 

Parents
  • Have you tried using the PS2 Connection and switching that, instead of USB?

    Best of luck,

    Jay 

  • Thanks for the suggestion Jay, whilst the Junior does have PS2 connections on the rear panel the Senior does not - it has USB only.

    I suppose this does beg the question " ... does the motherboard inside the Senior have PS2 connections that could be brought out to the rear of the panel somehow ..?" I guess I will have to go and have a look inside the Senior desk when it is free.

    I was also rather hoping for a reply from ETC to my question....

  • USB KVM switchers are a bit of a mixed bunch.

    Some of them are quite clever and act as a real 'host' to the USB keyboard & mouse, and present themselves to the host PC as real mice/keyboards even when switched the 'other way'.

    Some of them are just 'dumb switches', and simply contain a series of (hopefully) USB-spec switches to re-route the data to/from the relevant unit. (Think video crash-box)

    I'm not entirely sure which variety is better.
    The 'smart' KVM will switch faster, but runs the risk of misidentifying itself or the connected devices, while the 'dumb' KVM requires the host to re-identify the connected devices, and if it doesn't turn the connected devices off for long enough they may not attempt to re-connect.

    USB 2.0 adds an additional layer of complexity to this, as at the first attempt to connect it will try to use the full-speed USB 2.0, then again in High-Speed mode, and finally in USB 1.1 mode.

    As to the question of PS/2 - the ports do physically exist on a Congo Senior, but you can't access them as the CPU metalwork hides them.

    PS/2 KVMs are generally better as PS/2 isn't officially hot-pluggable, so all decent PS/2 KVMs host the keyboard & mouse themselves and pretend to be a single unit to the host.

    Unfortunately there does appear to be something strange with the KVM unit itself, so you'll need to contact that manufacturer.
    As a temporary workaround, you could simply use separate keyboards and mouses for the two consoles, only sharing the monitors themselves.

    If you can live with the slower USB pen drive access, it is possible to slow a Congo Senior down to USB 1.1 - however they've not been extensively tested in that configuration.



    [edited by: Richard at 5:41 AM (GMT -6) on Wed, Jul 02 2008] [edited by: Richard at 5:38 AM (GMT -6) on Wed, Jul 02 2008]
  • Hi Richard,

    Thanks for the information. We have been in touch with the American manufacturer of our KVM switches since we thought we may have a faulty unit - however we have tried 3 identical units now and each one gives unsatisfacory results so I think it is a case of we have innocently bought unsuitable units.

    With reference to your comment:

     Some of them are quite clever and act as a real 'host' to the USB keyboard & mouse, and present themselves to the host PC as real mice/keyboards even when switched the 'other way'.

    Could you recommend such a kvm switcher that we could try?

     

  • Unfortunately I've not had the chance to try out any USB KVMs on a Congo Jr/Senior pairing, so I'm hesitant to recommend any particular devices at present - I've only used PS/2 KVMs on Congo Lightservers and Jrs.

    I think Erik Larsen has tried some out USB ones - I'll point him at this thread and ask if he has any ideas.

Reply
  • Unfortunately I've not had the chance to try out any USB KVMs on a Congo Jr/Senior pairing, so I'm hesitant to recommend any particular devices at present - I've only used PS/2 KVMs on Congo Lightservers and Jrs.

    I think Erik Larsen has tried some out USB ones - I'll point him at this thread and ask if he has any ideas.

Children
Related