A socket is one endpoint of a two-way communication link between two programs running on the same network. Both programs can run on the same or different computers. In Crystal Instruments’ EDM software, a socket is implemented in the client-server model. EDM hosts the socket server and allows users to program their own socket clients to communicate with EDM. One socket server may communicate with multiple clients concurrently.
Socket messages are sent and received between EDM (the socket server) and socket clients. A socket client can send messages to EDM and may receive data or an acknowledgment message as a reply. Users can configure the event-action rules of a vibration control system (VCS) test to send socket messages to a socket client when certain system events occur.
Socket messages in EDM utilize the TCP/IP protocol and can be sent over the network interface or a serial port (depending on the interface provided by the computer where EDM is installed). The two-way communication feature of socket messages offers a reliable protocol for EDM to interact with external instruments.
A socket client may send messages to EDM to Start/Stop/Pause/Continue a VCS test. In addition, it may request the test status and live signal from EDM and display the message on the socket client itself. Crystal Instruments provides users with an example of a socket client to try out with all of the socket messages.
Crystal Instruments highly recommends users to customize their socket clients in order to better meet various requirements and achieve optimized test operation between the EDM software, external instruments, and socket client. The programming language of a socket client should be C#.
Starting from the EDM 7.0 release, a few socket messages are implemented to support creating tests with a given name, configuring the input channel table, configuring the profile and tolerances, setting a simple schedule (level and run duration), and basic test parameters. With the utilization of the aforementioned messages, it is possible to implement a one-click button to create a VCS test in EDM.
Starting from the EDM 8.0 release, new socket messages are implemented to retrieve the path of the run folder from the last run and the list of saved file names in the specified folder to allow socket clients to automatically fetch data files after the completion of the run. At this point, the three major parts of a VCS test (test configuration, test operation and retrieval of test results) are all supported by the EDM socket message feature.