# Scan Channels **URL:** \ **Category:** XBee - Zigbee\ **Created:** [July 28, 2011, 10:27am UTC](https://forums.digi.com/t/scan-channels/735 "2011-07-28T10:27:23Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![shedo](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@shedo](https://forums.digi.com/u/shedo)\ **Post date:** [July 28, 2011, 10:27am UTC](https://forums.digi.com/t/scan-channels/735/1 "2011-07-28T10:27:23Z")
Hi all, I’m new in the xbee world, and i have a question. I want to set Scan Channels and i understand how but i can’t understand how write the value. Example: I read in the manual that: if the operating channel is 0x0B, set SC to 0x0001. If the operating channel is 0x17, set SC to 0x1000. but I can not understand how calculate the number from 0x17 to 0x1000 or calculate range that i want… For example, setting SC to 0x281 enables scanning on channels 0x0B, 0x12, and 0x14, in that order. Can you help me? ---
**Author:** ![lynnl](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lynnl](https://forums.digi.com/u/lynnl)\ **Post date:** [July 28, 2011, 12:58pm UTC](https://forums.digi.com/t/scan-channels/735/2 "2011-07-28T12:58:55Z")
Why do you want to set this? Are you trying to force use of a single channel? This risks picking a useless channel. Normally, you leave the SC=0x1FFE in all devices and let the coordinator try to find a clear, usage channel. The other devices ‘scan’ through all enabled channels to find a coordinator. ---
**Author:** ![shedo](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@shedo](https://forums.digi.com/u/shedo)\ **Post date:** [July 28, 2011, 1:02pm UTC](https://forums.digi.com/t/scan-channels/735/3 "2011-07-28T13:02:41Z")
> Why do you want to set this? Are you trying to force use of a single channel? This risks picking a useless channel. > > Normally, you leave the SC=0x1FFE in all devices and let the coordinator try to find a clear, usage channel. The other devices ‘scan’ through all enabled channels to find a coordinator. thanks for the answer but i need to set the channel or the range channel… ---
**Author:** ![lynnl](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lynnl](https://forums.digi.com/u/lynnl)\ **Post date:** [July 28, 2011, 1:23pm UTC](https://forums.digi.com/t/scan-channels/735/4 "2011-07-28T13:23:21Z")
Okay, understand that there are 2 weird things here. First, Zigbee channels are numbered 11 to 26. Why? Are they planning to steal channels 0-10 from lower spectrum some day? heck if I know. Second, these are often given as hex, as 0x0B to 0x1A. Digi docs sometimes are a bit cavaler and just talk about channel 0D without including the 0x. So when you mention “17” - make sure you understand if you want 17 (so 0x11) or 23 (so 0x17) Do a Google search of ‘Zigbee channels’ and you’ll find lots of nice graphs and details. So \>MY UNDERSTANDING\< (which may be wrong) is that 0x281 would be channels 11, 18 and 20 (0x0B, 0x12 and 0x14). So the first channel (11 or 0xB) is 0x0001. ---
**Author:** ![shedo](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@shedo](https://forums.digi.com/u/shedo)\ **Post date:** [July 28, 2011, 1:35pm UTC](https://forums.digi.com/t/scan-channels/735/5 "2011-07-28T13:35:47Z")
Ok, but i can’t understand the mechanism to translate the sequence of channel (11,18,20) to hex number 0x281 or sigle channel 0xB to 0x0001. For example if i want set the sequence 12,13,16 how can calculate the corrisponding number? ---
**Author:** ![lynnl](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lynnl](https://forums.digi.com/u/lynnl)\ **Post date:** [July 28, 2011, 1:54pm UTC](https://forums.digi.com/t/scan-channels/735/6 "2011-07-28T13:54:28Z")
You are thinking too hard 🙂 Just write it down on paper (or Excel if you are fancy) 11 (0x0B) = 0x0001 12 (0x0C) = 0x0002 13 (0x0D) = 0x0004 14 (0x0E) = 0x0008 15 (0x0F) = 0x0010 16 (0x10) = 0x0020 17 (0x11) = 0x0040 18 (0x12) = 0x0080 19 (0x13) = 0x0100 20 (0x14) = 0x0200 21 (0x15) = 0x0400 22 (0x16) = 0x0800 23 (0x17) = 0x1000 24 (0x18) = 0x2000 25 (0x19) = 0x4000 26 (0x1A) = 0x8000 ---
**Author:** ![shedo](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@shedo](https://forums.digi.com/u/shedo)\ **Post date:** [July 28, 2011, 2:14pm UTC](https://forums.digi.com/t/scan-channels/735/7 "2011-07-28T14:14:20Z")
Thanks alot… 🙂 then if i want a set of channels should i sum the respective value? ---
**Author:** ![lynnl](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lynnl](https://forums.digi.com/u/lynnl)\ **Post date:** [July 28, 2011, 2:35pm UTC](https://forums.digi.com/t/scan-channels/735/8 "2011-07-28T14:35:41Z")
Yes - technically you ‘OR’ them together, but adding/summing should work as well. I created a wiki page for you: [http://www.digi.com/wiki/developer/index.php/Channels%2C\_Zigbee](http://www.digi.com/wiki/developer/index.php/Channels%2C_Zigbee) So if you want the four channels which do not overlap the standard 3 WiFi bands, you’d want ZB channels 15, 16, 21, and 22. So you would set the coordinator’s scan\_channel/SC to 0x0C30. Generally, leave all other nodes with the default SC. They will waste a small amount of time during the original association, but it allows you to change your mind more easily in the future & only change one SC value. ---
**Author:** ![shedo](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@shedo](https://forums.digi.com/u/shedo)\ **Post date:** [July 28, 2011, 4:19pm UTC](https://forums.digi.com/t/scan-channels/735/9 "2011-07-28T16:19:04Z")
Thanks alot for all… You helped me alot!!! 🙂 ---
**Author:** ![Diegui12](https://avatars.discourse-cdn.com/v4/letter/d/a9a28c/32.png) [@Diegui12](https://forums.digi.com/u/Diegui12)\ **Post date:** [March 4, 2015, 12:20am UTC](https://forums.digi.com/t/scan-channels/735/10 "2015-03-04T00:20:41Z")
Hello guys. I’m trying to scan just one channel. II’m using waspmote v1.1 and xbee 802.15.4 S1. I tried using the example [http://www.libelium.com/development/waspmote/examples/802-07-energy-scan/#](http://www.libelium.com/development/waspmote/examples/802-07-energy-scan/#) But appears the following error: C:\Users\Diegui\Desktop\Papeo\Ramos\Teoría de Información y Código\Software\waspmote-ide-v.01-windows\hardware\cores\wasp\_v018/WaspXBeeCore.h:1621: error: ‘Sd2Card’ does not name a type In function ‘void setup()’: In function ‘void printEnergyChannel()’: Bad error line: -4 What does this mean ? Please any help