Using the NI cDAQ-9191 Web API you to wirelessly communicate to a NI cDAQ-9191 using a standard HTTP request from a computer or mobile device. The Web API allows you to perform three interactions with the NI cDAQ-9191. This functionality is split between two uniform resource identifiers (URIs): a Configuration URI and a Data URI.
Send a GET request to the Configuration URI to receive the current state of the chassis
Send a POST request to the Configuration URI to configure a task and update the firmware
Send a GET request to the Data URI to acquire data from a configured task
The NI cDAQ-9191 Web API uses JSON to communicate its configuration. JSON is a serial object representation format similar to XML. For more information, go to http://www.json.org.
Samples from the device are returned as binary data.
Each sample is an IEEE 32-bit floating point number in network byte order. You may need to reorder the bytes depending on your system.
Measurements from multiple channels are interleaved, so you must read the first sample from every channel in your task before you receive the second sample.
The chassis must be on the same subnet as your iOS device.
The chassis host name or IP address
All the examples require a "Host Name", which is the name you configured for your NI cDAQ-9191. You can also use its IP address in this field. For more information on discovering your NI cDAQ-9191's IP address and name, refer to NI Network Browser.