# Programming Basics **Content** * Device service API programming * Verify device service APIs * Reference ## Device Service API Programming ### **API Convention** For EdgeX device service's RESTful APIs, it usually uses two parameters, device and command. * Device: represents physical device or resource, for example battery, disk, Wi-Fi... * Command: represents physical sensor node or single I/O port, for example, battery temperature, disk total capacity, Wi-Fi's IP... In each device service's APIs, it will list the supported devices and names. EdgeX Device service uses two options to specify the device and commands. One is by ID (generated by database) and other one is by name. URL Call by ID ``` http://localhost:48082/api/v1/device/{deviceId}/command/{commandId} ``` URL Call by name ``` http://localhost:49987/api/v1/device/name/{deviceName}/{commandName} ``` Note: the port 49987 depends on the device service. ### **URL Call by ID** For the one by ID, EdgeX provides the following REST API to get device and command ID ``` http://localhost:48082/api/v1/device ``` Note: localhost is replaced by the physical device IP. ![](https://1210863923-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2Fedgex-api-doc%2F-LephlKT9eCoySEWjPKb%2F-LepsxrOfuxfi3mqB6zX%2F8.png?generation=1557829784878650\&alt=media) In the above example, for Advantech-IPSM90-01 device * deviceId is 5cb809a79f8fc20001ddad32 and * Battery\_Temperature’s commandId is 5cb809a79f8fc20001ddace8. Replace "edgex-core-command" with physical device IP (for example 172.16.8.87) and use web browser to send the following command to get Advantech-IPSM90-01’s Battery\_Temperature. ``` http://172.16.8.87:48082/api/v1/device/5cb809a79f8fc20001ddad32/command/5cb809a79f8fc20001ddace8 ``` ### **Examples** Get temperature from Advantech-IPSM90-01 by device ID ``` http://172.16.8.87:48082/api/v1/device/5cb809a79f8fc20001ddad32/command/5cb809a79f8fc20001ddace8 ``` Get temperature from Advantech-IPSM90-01 by device name ``` http://172.16.8.87:49987/api/v1/device/name/Advantech-IPSM90-01/Battery_Temperature ``` ### **Response** HTTP response code * Success Response: ``` Code: 200 ``` * Error Response: ``` Code: 503 Content: service unavailable ``` * Success Content Example (GET) ![](https://1210863923-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2Fedgex-api-doc%2F-LephlKT9eCoySEWjPKb%2F-LepsxrPJc_OMi4vG5XA%2F9.png?generation=1557829784865468\&alt=media) **​** device field: the specified device name\ name: the specified command name\ value: returned value for the specified device and command ## Verify Device Service APIs There are two ways to verify device service APIs or RESTful APIs, cURL tool or Postman tool. Example: verify the API to get temperature from Advantech-IPSM90-01 by device name ### **cURL** The following example use curl tool to set Battery\_AlertStatus to 1 ``` curl -X PUT -H "Content-Type: application/json" -H "Cache-Control: no-cache" -d '{"Battery_AlertStatus":"1"}' "http://172.16.8.87:48082/api/v1/device/5cb809a79f8fc20001ddad34/command/5cb809a79f8fc20001ddcfe" ``` ### **Postman** Input the fields * method: GET (on the top left) * URL: Then press "Send" button. The result is shown as below * Status: 200 OK * value: 28 (in the response Body field below) ![](https://1210863923-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Ldahy90A1eekcr5A2U8%2F-Lf-67huYPRcA3kGn7Vc%2F-Lf-8UQqFDBCuXDCOiO4%2Fimage.png?alt=media\&token=8259070f-4015-4f6d-9de2-53c460f4b2c8) ## Reference * Postman download link: * cURL installation and using cURL: --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://edgex-api-advantech.gitbook.io/edgex-api-doc/device-connection/programming-basics.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.