Max No. TPs per System and Max No. TPs per WAP
syslock
Posts: 45
Hey everyone I was wondering if any one knows if there is a maximum number of touch panels you can have on 1 system and keep them all online all the time and also what is a maximum No. of connected touch panels to a AMX NXA-WAP250G before strange things start happening.
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That is completely dependant on what your project is like. (practically). So it depends on the network situation there.
In theory it's 32 clients per VAP, so that's 64 clients in total. (The 250 supports 2 VAPs.)
Touchpanels is completely dependant on the configuration, how many ports etc you use per touchpanel, how many updates need to be send, how actively the system will be used. Wireless + cabled, or just wireless etc. Max number I used on 1 system was 26, but that's R4s + Wireless Panels + Wired panels, no issues there.
The WAPS all have the same SSID and in each boardroom I use channels 4, 8, 13 the SSIDs are the same because the TPs are dynamically assigned to the boardrooms and then the seats from storage when needed. The building also already has a wireless infrastructure network running on channels 1, 6 and 11
"In theory it's 32 clients per VAP"
Thanks I didn't know that.
I've logged the online offline status of the TPs for the day so far to text file.
They'll fall offline, and come back online a lot if there's a lot of interference on the network (wireless). The best way to check for interference is to use a scanner like Wi-Spy and see if you can trace it down. Changes are there are WAPs in the neighbourhood that keep changing their channel and those would then be interfering with your WAPs in turn interfering with your Wireless Panels. The dB strength from the panels isn't so high, so even little interference will kill it with certain events.
Another point might be that your WAPs are switching channels and are going further than channel 11, in the USA the only wireless channels that you are allowed to use are channels 1-11. So AMX Panels only go that far, in most european countries it's 1-13. If the panel then can't connect because the WAP is on the wrong channel for a period of time. (if it's on 13 you might be able to connect to it over channel 11, but the connection wont be stable) your panels might fall offline and come back online.
There might also be other 2.4Ghz equipment interfering. Devices such as Zigbee and others.
That means that those 2 are interfering with each other, so both should be on 1, 6, 11 if that is achievable.
channel 1: 1 .. 3
channel 4: 2 .. 6
channel 6: 4 .. 8
channel 8: 6 .. 10
channel 11: 9 .. 13
channel 13: 11 .. 15
Only if your channel bandwith is set to 20Mhz btw. (1 channel = 5Mhz in that case, 4 channels are used for broadcast so that means 20Mhz)
AMX doesn't handle channel 13, so that might explain why your pannels are going offline (they're trying to connect to your WAP using channel 11, which is the weakest point when sending out on channel 13)
Because there is so much overlap you have a lot of interference.
Lemme draw it out for you:
The bandwidth you have left is everything above the red line.
No problem.
Most of it is network related. The idea is good, the effect is the opposite of it though.
Edit:
Or when they lose signal (be it intentional or not)
Apart from that Offline/Online events also (mostly) have an impact on your processor's load.
If you want redundancy, use WDS, not multiple access points on different channels. Then they will all be on the same channel per room, and there is less opportunity for interference, and less access point hopping.
WDS doesn't give you redundancy WDS enables you to extend your wireless network without cables. What you're referring to is a Wireless Mesh Network, that gives you redundancy as well, because if route A fails they'll go via route B. (wireless as well)
And in the way you're saying it the AP would need to have enough distance between them not to interfere too much and not too much distance because then the network quality would suffer, WDS is not something you should attempt in an environment where you have too little influence on things (placement etc).
In the end you don't need this if you just set up a wired network, as that will always be more stable and faster.
The best would be if you set it up to channels 1, 6, 11 with active roaming on the panels, where the SSID is still the same. But to do that he'll have to match them with the current system, so where there's an WAP on channel 6 he'll have to choose 1 or 11, which again is dependant on the rest of the network. But if he can he should match these that way. Without knowing the physical layout of the rooms and the where and how things are connected this will proof to be a difficult task.
So to sum up:
First prize is to convince the banks IT department to allow us to use the existing wireless network.
Second prize to setup a network using channels 1, 6 and 11 making sure not to use channels in the same area as the banks existing wireless network.
I didn't know that either.
Yes and no. If a repeater station fails, you can still potentially pick it up from the base or another repeater, and there's your redundancy. I was thinking in terms of this specific scenario, there it seems to me there is a fair amount of overlap.
My feeling is that this is exactly his problem. The real, if minimal, disconnect when it's roaming from one channel to another. I propose he needs to get rid of the multiple channels, period. You are right that a mesh would be better than WDS (that was just the first thing that occurred to me), but I really think he needs to eliminate the roaming. What with competing wireless in other areas, every time a panel hops from one WAP to another he is getting a noticeable delay.
So what you should do in this situation is prize 2 + hide your SSID so regular folks don't even see your network. Try to cover the areas well with your network, so you don't leave any gaps. Interference also comes back in to play again, so if their config in a room is:
1 - 6 - 11
yours should be:
11 - 1 - 6 or
6 - 11 - 1
Ideal placement is nasty to work out, but often unnecessary. Just be sure you don't cause interference on other parts of the network(s).
Just to clarify it's channel 12-13 (and technically 14) that it doesn't pick up.
Edit:
Depending on the size of these boardrooms, but I can't actually imagine you'd need more than 1 AP per boardroom, let alone more than 2.
Considering the channels he's broadcasting on himself the real issue lies within that. Active roaming shouldn't cause the panel to go offline though, or rather I haven't seen that happen when I used it. Depending on the placement of the WAPs it might or might not be a good idea to put them on the same channel, apart from how the wireless panel will pick that up.
Define 'regular?' With an AMX TP constantly talking to a master, I would get that SSID no problem. I don't even try. But I would hope the WPA(2) stops me...
Good placement isn't hard with the right tools, but sometimes is made difficult by the building
If possible yes, but they don't want him on their network. So I excluded that. Chances are the project manager doesn't know what you are on about and if they ask their IT they would probably ask it in a way that they'll get a 'no, insecure' answer. But if you can get them to agree to that it would/could be the best situation. Worth a shot at least.
Even without traffic you would need to be stopped by the encryption, not the hiding of the SSID or say MAC control.
Regular folk: The none-IT people in the building & not tech-savvy people
My point exactly, and if you don't have it/can't get it or don't know how to do it. Hire a company that does. You'll get a full report and you'll be able to build your network from there.
Chances that you'll get that through in a bank are slim though.
It is not hard for wireless systems to squash, or at the very least cause major headaches, to unauthorized wireless access points within their air space.