There is CTS and RTS HARDWARE FLOW CONTROL. My question is
how to use flow control in xbee802.15.4 test?
this afternoon I selected hardware in X-CTU software, but I still don’t know how to use flow control of xbee. Who can help me?in X-CTU, if I choose assert RTS, which means that RTS keeps lower. And CTS IS ALWAYS GREEN. How can I check CTS STATE IN X-CTU? If it is not allowed in x-ctu, Can you tell me how to poll it?
2.In flow control in x-xtu, there are three options. hardware, software(Xon/Xoff), None. What’s difference in testing?
3.What does DSR mean in X-CTU ?
4.What does DTR mean in X-XTU?
On datasheet of xbee802.15.4, there are sentence"If RTS is enabled for flow control (D6 (DIO6 Configuration) Parameter = 1)". What’s the relationship between RTS and D6?
My test results:
The reason is that data from RX xbee always move forward at every about 1000 bytes, when I transmit data from TX xbee with delay of 1ms.The moving forward reason, I found that it is always 1or 2 bytes are lost on RX Xbee when about 1000bytes are sent from TX xbee. So if I transmit data with delay but repeatly, there are shifting forward in receiving data in RX xbee.
While less than 1000bytes data is sent, on RX Xbee no lost happen. So I want to poll CTS and RTS state when communication. But I failed.
My problem is that RX XBEE data is always shift forward 1 byte for every about 1000 bytes, which causes diamatching between RXdata and TXdata.It brings problem in RXdata process in matlab.
I want to find the true reason and solve the kind of shifting forward in RXdata.
Do you have any suggestion?
The test result:
The reason is that data from RX xbee always move forward at every about 1000 bytes, when I transmit data from TX xbee with delay of 1ms.The moving forward reason, I found that it is always 1or 2 bytes are lost on RX Xbee when about 1000bytes are sent from TX xbee. So if I transmit data with delay but repeatly, there are shifting forward in receiving data in RX xbee.
While less than 1000bytes data is sent, on RX Xbee no lost happen. So I want to poll CTS and RTS state when communication. But I failed.
With series 1 Bees I recall a firmware I recall long, long ago (1+ years) that there was a firmware bug flow control.
Generally, I would never rely on the MAC itself for a reliable datagram service. 802.15.4 does have an option, normally enabled, for error detection via CRC, with n retries. Nothing more.
Hence the need for a standard or minimal unique protocol for transport/network layer flow control and error correction
ceibawx:
What kind of acknowledgment from two xbees talking?
HOW to tell TX XBEE that all data sending is finished?
It is data length that I sent, right?
What kind of setting I should do if I want to see this acknowledgement in X-CTU?How can I get acknowledgment from RX xbee?
THANKS.
I got a red acknowledgment on TX XBEE X-CTU window, and the acknowledgment is from TX XBEE. IT told me all the data length is “960*3”.
And on the RX XBEE X-CTU, I also saw the same acknowledgment, but blue color.
But now it disappear when I tried again. Who can tell me how I can make it happen again?
Thanks.
PS: I chose hardware in flow control.
The XBees (and others) will move data to/from each end of the wireless link. Using a MAC and PHY (read about these terms). No wireless medium is error free. The MAC and PHY will correct some but not all errors. The rest is up to you. It is also up to you to have a mechanism (protocol) for data management including a way for the sending and receiving systems to agree on what constitutes a complete message. These are called application protocols. The same holds true for wired connections, though the error rate is lower.
A good idea is to understand how ethernet MAC and PHY work, and the UDP and TCP protocols. Then decide how alike you need your end to end to be, and build simplified versions of these. Essentially, 802.15.4 itself is similar to sending ethernet packets using ethernet MAC addresses. Next step up is using UDP.