We have a customer that will not allow the VC-4 to connect to their corporate network, but there is a guest wireless network that would easily allow the VC-4 to check in with XIO Cloud. I asked Crestron if there was a way to enable the wireless adapter so I could join it to the guest Wi-Fi but was told it was disabled in BIOS.
Time passes, and the VC-4 license expires and won’t run the room programs anymore. In a pinch, we swap the VC-4 for an RMC4 so the room can function again. Now I’ve got the VC-4 back in the shop to see about enabling the Wi-Fi.
Checking the BIOS settings, Wi-Fi is enabled, and when I check the kernel boot messages, it does load a driver for an Intel wireless adapter:
$ dmesg | grep -i wifi
[ 6.284577] Intel(R) Wireless WiFi driver for Linux
[ 6.285545] iwlwifi 0000:00:14.3: enabling device (0100 -> 0102)
[ 6.287743] iwlwifi 0000:00:14.3: Detected crf-id 0x3617, cnv-id 0x20000302 wfpm id 0x80000000
[ 6.288426] iwlwifi 0000:00:14.3: PCI dev 06f0/4070, rev=0x351, rfid=0x10a100
[ 6.303287] iwlwifi 0000:00:14.3: Direct firmware load for iwlwifi-QuZ-a0-hr-b0-78.ucode failed with error -2
[ 6.605209] iwlwifi 0000:00:14.3: api flags index 2 larger than supported by driver
[ 6.605911] iwlwifi 0000:00:14.3: TLV_FW_FSEQ_VERSION: FSEQ Version: 89.3.35.37
[ 6.607126] iwlwifi 0000:00:14.3: loaded firmware version 77.206b0184.0 QuZ-a0-hr-b0-77.ucode op_mode iwlmvm
[ 7.105957] iwlwifi 0000:00:14.3: Detected Intel(R) Wi-Fi 6 AX201 160MHz, REV=0x351
[ 7.222327] iwlwifi 0000:00:14.3: Detected RF HR B5, rfid=0x10a100
[ 7.288754] iwlwifi 0000:00:14.3: base HW address: f8:9e:94:c5:0b:1b
[ 7.609423] iwlwifi 0000:00:14.3 wlo1: renamed from wlan0Looks like wlo1 is our network adapter, so I try connecting using nmcli:
$ nmcli dev status
DEVICE TYPE STATE CONNECTION
eno2 ethernet connected eno2
lo loopback unmanaged --
wlo1 wifi unmanaged --Hmm, I Google for answers and find that maybe the wireless radio is turned off, so I try:
$ sudo nmcli radio wifi onThat still doesn’t let me manage wlo1. It looks like the firmware for the Intel wireless adapter isn’t installed, so I run:
$ sudo dnf install linux-firmwareI also read that NetworkManager may need a plugin for Wi-Fi support, so I run:
$ sudo dnf install NetworkManager-wifiDo a reboot to make sure everything gets loaded, then I issue:
$ sudo nmcli dev wifi listI see my access point, so I issue:
$ sudo nmcli --ask dev wifi connect <SSID>Ta-da! Internet! I do another reboot to make sure the connection still works and it does.
So while Crestron saying the Wi-Fi was disabled in BIOS turned out to be false, there were some missing packages I had to install before I could get it online. It would have been difficult to do this at the customer site where getting an Internet connection to download those packages was impossible.
Kiel the Coder 
We asked Crestron TB about this and they said that if enabled, once it goes offline, it throws a bunch of errors and could lock the unit up. I’m curious if you have found anything like that yet or if they were just talking out of their butts.
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Hi J, I’m not sure if I’m testing this the same way Crestron is worried about, but it looks like it works fine for me. I’ve got a SIMPL debugger session running, connected via my laptop through an isolated network switch to the VC-4. I deactivated the Wi-Fi connection on the VC-4 and it doesn’t seem to affect the running program. I do see some error messages in the logs about HydrogenManager not being able to reach XIO Cloud, but those were there when I had no Internet access anyway. XIO Cloud says the device is still online, but I’ve noticed it’s slow to refresh anything. CPU and memory load on the VC-4-PC-3 hasn’t drastically changed either. I’m going to let it run like this for a few days and see if anything in the running program stops working.
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Good post.
Crestron is full of it. I’ve never seen a VC-4-PC-3 with radio disabled in the BIOS. I normally actually manually turn all radio off and put them in airplane mode after updating my VC-4 systems. I’m not even certain that VC-4 systems actually need to “check-in” at this point and that this is just some myth that seems to be spread via FUD through the industry. Just that it needs an XIO cloud connection to perform the initial license transfer. I’ve got my own “VC-4-PC-3” system that I built that’s been running just fine without a license for the better part of a year. Based upon what I’m seeing in the field, even after licensing them they may not need to “check in”.
As a Linux veteran of nearly 30 years (and mainly a user of Fedora/RedHat for several years now), Crestron’s implementation on the VC-4-PC-3 incorporates a lot of bad practices that need some cleanups. Recent system images seem to be better but they were atrocious a year ago. As far as AlmaLinux goes, I hate to give away some of my trade secrets but you can also install the “Server with GUI” group via YUM and gain a GNOME desktop that gives you a lot of additional flexibility (much of which is not going to be officially “supported”) but among them will be the NetworkManager updates / firmware and the ability to set WiFi via GUI that simplify everything listed above (bare minimum you need a monitor or EDID emulator for remote desktop access). But I’ll just say that there are a multitude of powerful things that you can do with VC4-PC-3 being that it’s an open Linux system. It’s my opinion that none of these systems should be installed without the security updates, and I even enable firewalld. But Crestron probably would disagree because to them it’s “an appliance” like how they treat the AutomateVX. But I would like to suggest that no real Linux admin would leave unpatched servers running their VC-4 installations in a VM.
Anyway… You can also use the console application “nmtui” to perform the functions that you list above. RHEL (and binary comparable systems like AlmaLinux) store the configuration scripts in /etc/sysconfig/network-scripts/ so it’s technically possible for you to just drop them in there and set the user / group / mode (keys-APname which stores the WAP password is chmod 600).
One important thing to note: It would be a good idea to disable the network gateway on an interface that you don’t want to try to talk to the Internet w/. That is, if you have LAN on an isolated system and then set up WiFI with DHCP, disable the gateway on the wired LAN. You can see w/ “ip route” just how the routing tables are set up, but disabling the gateway on an interface is the most simple solution. Or if you build a “control subnet”, do the same on your USB to LAN adapter. Don’t use Crestron’s horrible DHCP server script either. “Isolation mode” isn’t supported on a VC-4-PC-3 but it most certainly works if you know how to set it up.
I love the VC-4-PC-3. It’s my favorite Crestron control system. TBH, I’d love it if I never saw another standard 4-Series again and every control system was a VC-4-PC-3 at this point. I do think that their licensing needs to change a bit though, considering that a CP3/4 had 10 program slots and a VC-4-PC-3 technically only has 3 (rooms) without adding licenses. But the best part is the amount of flexibility that you gain with an AlmaLinux system.
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Thank you for the Linux admin tips, Mr Karate. I agree, having a Linux system ends up being much more flexible. I can understand Crestron probably wanting to lock things down to a certain hardware / OS combination to make their support easier. I’m more familiar with Debian, but it hasn’t been too bad to learn the RedHat equivalents of things.
I don’t know if it’s from a certain VC-4 version onward, but our customer definitely had a PC-3 that stopped running programs. I did the initial licensing in xio cloud from our office and about 90 days later, the running programs stopped and the web UI said licensed for 0 rooms. We had warned them that this device needed access to the Internet, but their network team wouldn’t allow traffic outside that VLAN. Ultimately, we replaced the VC-4 with a CP4 to take the burden off their IT team. I got the VC-4 back onto our office network, and it started running programs again.
Crestron had a great deal going for a while when they introduced the VC-4-PC-3: 7 free licenses to round it out to 10 rooms. I wish I would have taken advantage of that for a lab setup, but in reality we weren’t selling a lot of VC-4. We ended up switching to more Q-SYS since it was readily available.
Wish I could comment some more on all that you’ve shared, but doing this from my phone and the comment box is 3 lines tall.
Thank you for sharing your tips!
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