Hello, first thing to do or verify is that you have set the component to be registered as Local Server, and un-checked the registration as In-Process Server. These are the settings we support for PHP. For details, see the user's guide (Concepts), or this thread: www.opclabs.com/Support/Online....
If this does not help, I can think of 3 reasons to this error:
a) The OPC server may genuinely take too long to perform the read. This would be unusual, as the default timeout setting is 60 seconds, but it is not forbidden. In such case, increasing the timout would resolve the problem. The timeout can be increased in the "default", by the utility installed with the component, or from inside your program, using a property in the "mode" object. Let me know if you need further instructions to this.
b) A bug in the OPC server may cause it to block indefinitely in some call.
c) A bug in the component may cause it.
If we come to opinion that we need to figure out between b) and c), the way forward would be to either reproduce the problem here, or analyze the communication between thye component and the server with special tool(s) that we can provide to you.

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I have install the "QuickOPC-COM free fully-functional trial" and it works, I really love it,but it always failed after few minutes with message "Fatal error: Uncaught exception 'com_exception' with message 'Source: OPCLabs.EasyDAClient.5.0
Description: Read not completed. This error indicates that it could not be verified that the requested read operation was completed during the timeout period. It is possible that the read operation will actually succeed or fail, but later. Increase the timeout period if you want to obtain positive or negative indication of the operation outcome. Other reason for this error may be that under heavy loads, topic request or response queue is overflowing. Check the event log for queue overflow errors. ' in E:\xampp\htdocs\opc1\get_txt.php:25 Stack trace: #0 E:\xampp\htdocs\opc1\get_txt.php(25): unknown() #1 {main} thrown in E:\xampp\htdocs\opc1\get_txt.php on line 25". How can I solve it? Thanks a lot! Submitted By: k.