I can see how a datastream/channel can be used to send commands to a device (e.g. an actuator). The device can periodically poll the channel for incoming commands, but if the device has no storage of its own how can it tell which commands it has already received/processed?
Xively: sending commands to devices - how to mark commands as read?
287 Views Asked by RobM At
1
There are 1 best solutions below
Related Questions in XIVELY
- Google IoT with Xively API availability
- Whats the error refer to connect xively using master api key? SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:645)
- Xively Personal - was working but now data does not change
- Xively and keypad.h
- Xively Device Activation Code does not match using HMAC-SHA1 algorithm
- Server error upon adding new device leads to duplicate devices
- Python: pushing sensor data from Raspberry Pi to xively
- Is Xively web socket down?
- Xively error using json
- Pulling data from web server on android not updating
- Xively displays incorrect timestamp when logged out
- Sending data to Xively using Arduino mega + GSM shield sim 900
- New Xively server error (503) on production system
- How to pull data from Xively without authentication?
- xlively conversion from Pachube Feed VB.net
Trending Questions
- UIImageView Frame Doesn't Reflect Constraints
- Is it possible to use adb commands to click on a view by finding its ID?
- How to create a new web character symbol recognizable by html/javascript?
- Why isn't my CSS3 animation smooth in Google Chrome (but very smooth on other browsers)?
- Heap Gives Page Fault
- Connect ffmpeg to Visual Studio 2008
- Both Object- and ValueAnimator jumps when Duration is set above API LvL 24
- How to avoid default initialization of objects in std::vector?
- second argument of the command line arguments in a format other than char** argv or char* argv[]
- How to improve efficiency of algorithm which generates next lexicographic permutation?
- Navigating to the another actvity app getting crash in android
- How to read the particular message format in android and store in sqlite database?
- Resetting inventory status after order is cancelled
- Efficiently compute powers of X in SSE/AVX
- Insert into an external database using ajax and php : POST 500 (Internal Server Error)
Popular # Hahtags
Popular Questions
- How do I undo the most recent local commits in Git?
- How can I remove a specific item from an array in JavaScript?
- How do I delete a Git branch locally and remotely?
- Find all files containing a specific text (string) on Linux?
- How do I revert a Git repository to a previous commit?
- How do I create an HTML button that acts like a link?
- How do I check out a remote Git branch?
- How do I force "git pull" to overwrite local files?
- How do I list all files of a directory?
- How to check whether a string contains a substring in JavaScript?
- How do I redirect to another webpage?
- How can I iterate over rows in a Pandas DataFrame?
- How do I convert a String to an int in Java?
- Does Python have a string 'contains' substring method?
- How do I check if a string contains a specific word?
This all depends on your implementation and hardware choices. And the real answer to this question lays far beyond the scope of Xively. You say that the device has no storage of its own, but I assume it has some kind of volatile memory at the very least.
The best thing to do would be to store the timestamp of the last datapoint that was received and compare it to whatever current data you have. If the timestamp is greater than the one in memory then you know it is new data.
An alternative to HTTP polling would be to use a socket with some kind of publish/subscribe interface that will allow you to received only new data from the server. Xively offers this on it's TCP, WebSockets, and MQTT socket servers.