Hello everyone!
Guyz I’ve been working in deveplopment of a product using RF communication. I want to know the exact working of the SC parameter? How can I select channel by using it? Whether this frequency (SC) selection affect the range and stability of the network?
awaiting precious replies!!
On a coordinator, the SC command sets a list of channels the coordinator can possibly start on. To force the coordinator to start on a fixed channel, set one bit in the SC mask. For example, to force the coordinator to start on channel 0x0C (2410 MHz), set SC=0x02 (“ATSC2”). Forcing a fixed channel on the coordinator is not recommended though. If multiple channels are enabled in SC, the coordinator will do an energy scan and try to select a channel with low detected energy. This can help the network start on a channel with less interference and should ultimately improve network stability.
Routers and end devices scan all SC channels to try and find a valid network to join. As a good rule of thumb, SC should be set the same on routers and end devices as it is on the coordinator.
Range is not significantly affected by the channel selection.
Thanks damons (actually i was unable to use my aahmed account thats why i’ve created this new id)
that clearified my doubts!
> For example, to force
> the coordinator to start on channel 0x0C (2410 MHz),
> set SC=0x02 (“ATSC2”).
Why? how can I calculate the sc value from the channel one? which value have I set if i want to communicate on channel “10”?
See the XBee product manual for details on the SC command. In a nutshell, the SC command is a bitfield that specifies which channels should be scanned when starting (coordinator) or joining (router /end device) a network. The channels range from 2405-2480MHz and each channel is 5MHz apart from each other. In 802.15.4 terminology, these correspond to channels 0x0B - 0x1A in the 2.4 GHz band.
For example, setting SC=0x0001 enables the lowest channel (channel 0x0B) on 2405 MHz. Setting SC=0x000F enables the lowest 4 channels (0x0B - 0x0E), or 2405, 2410, 2415, and 2420 MHz.
If you want to communicate on channel “10”, chances are you are referring to channel 0x10 (16 decimal). Set SC=0x20 to force scanning on this channel only.