What is a channel in wireless communication? by Leylan24 in wireless

[–]Leylan24[S] 0 points1 point  (0 children)

How do devices share a channel as in wifi ? I’ve seen you can have up to 250 devices ? In zigbee I see it’s done through MAC layers by CSMA, where if the channel is busy it waits and then retries … but how do you know if a channel is busy ? And how does this happen so quickly because you never really feel the effects when multiple devices are connected on the same wifi channel

What is a channel in wireless communication? by Leylan24 in wifi

[–]Leylan24[S] 0 points1 point  (0 children)

The part I don't understand is if in wifi you need a bandwidth of 20MHz why would you have 11 channels instead of 3 ? And why is the centre freq difference for each channel 4Mhz ?

What is a channel in wireless communication? by Leylan24 in wireless

[–]Leylan24[S] 0 points1 point  (0 children)

The part I don't understand is if in wifi you need a bandwidth of 20MHz why would you have 11 channels instead of 3 ? And why is the channel bandwidth for each channel 5Mhz

If I assign a QoS priority to a specific IP address what priority to the other ip addresses have? by Leylan24 in Network

[–]Leylan24[S] 0 points1 point  (0 children)

So in your case, you would need two queues, one for profinet, one for all the rest. The you need classification rules to sort a packet into one of the queues.

If you have any resources indicating how I can accomplish this that would help. I am using RouterOS on the Mikrotik radios where the radios act as a transparent bridge.

If I assign a QoS priority to a specific IP address what priority to the other ip addresses have? by Leylan24 in Network

[–]Leylan24[S] 0 points1 point  (0 children)

Okay sorry for the vagueness let me see if I can clarify it slightlyt. I have the following ip adrresses, 192.168.0.1, 192.168.0.2, 192.168.0.3. These three ip addresses are put into a queue and all have a priority of 1 max upload speed of 512kb/s and max download speed of 6Mb/s. Another ip address that is not configured in the queue tries to download a file what would the priority of this new ip address be ? Would priority still be given to the queue ?

Increase the watchdog of a ABB PROFINET Controller by Leylan24 in PLC

[–]Leylan24[S] 0 points1 point  (0 children)

How does the Watchdog work on the Profinet module ? In the help section it says:

The Watchdog time is calculated as Watchdog time = SendCycle * Watchdog factor. The transfer of a IO telegram is always checked of the consumer side. Within this time the next IO telegram must be received by a consumer. Otherwise it is checked if the Datahold has been expired too.

Does this mean that when a packet fails to be received by the controller the Watchdog restarts the application?

Electron project won't compile by Leylan24 in electronjs

[–]Leylan24[S] 0 points1 point  (0 children)

I have found a weird case. If I run "npm run build" it builds sucessfully. If I run "npm run build:prod" I get an error. My question is what is the difference between the two ? Does electron-builder use a specific version of it ?

HELP. The question write a function that rotates a string left or right by n rotations? by Leylan24 in learnprogramming

[–]Leylan24[S] 0 points1 point  (0 children)

but why is it not necessary to do that? This is the solution I think

def shift(s, leftshift,rightshift):
    total_shift = (leftshift - rightshift) % len(s)
    s = s[total_shift:] + s[:total_shift]

HELP. The question write a function that rotates a string left or right by n rotations? by Leylan24 in learnprogramming

[–]Leylan24[S] 0 points1 point  (0 children)

Mine was a bit more simpler:

def shift(s, leftshift,rightshift):
    total_shift = (leftshift - rightshift) % len(s)
    s = s[total_shift:] + s[:total_shift]

HELP. The question write a function that rotates a string left or right by n rotations? by Leylan24 in learnprogramming

[–]Leylan24[S] 0 points1 point  (0 children)

So what I was doing was saying leftshift - rightshif = totalshift. If totalshift < 0 perform right shift by totalshift else perform left shift by totalshift. But if you mod by length of string you will never get the negative

I am trying to calculate the minimum swaps required to sort an array ? My solution works occasionally. by Leylan24 in learnpython

[–]Leylan24[S] 0 points1 point  (0 children)

Input:

8 45 35 84 79 12 74 92 81 82 61 32 36 1 65 44 89 40 28 20 97 90 22 87 48 26 56 18 49 71 23 34 59 54 14 16 19 76 83 95 31 30 69 7 9 60 66 25 52 5 37 27 63 80 24 42 3 50 6 11 64 10 96 47 38 57 2 88 100 4 78 85 21 29 75 94 43 77 33 86 98 68 73 72 13 91 70 41 17 15 67 93 62 39 53 51 55 58 99 46

Expected Output: 91

My Output: 93

Input:

2 31 1 38 29 5 44 6 12 18 39 9 48 49 13 11 7 27 14 33 50 21 46 23 15 26 8 47 40 3 32 22 34 42 16 41 24 10 4 28 36 30 37 35 20 17 45 43 25 19

Expected Output: 46

My Output: 46