ZKTeco SDK ReadAllUserID() fails with error -115

Question

I'm using ZKTeco sdk to connect to a device, the connection works fine, but anything that requires reading large data fails.

ReadAllUserID fails with error -115

            if (!axCZKEM1.ReadAllUserID(1)) {
                Log("ReadAllUserID failed.");
                int errorCode = 0;
                axCZKEM1.GetLastError(ref errorCode);
                Log("ErrorCode=" + errorCode); // ErrorCode=-115
            }

SDK: standalone+sdk-6.3.1.37-doc-2.1.0-demo-1.1.15.

OS: Windows 7 x32.

Device: Door Access, Model: ACP-260

The machine is using the new protocol (i.e. The TCP version not the old UDP version).

Answer 1

The ReadAllUserID returns false because you should probably be using the Pull SDK instead of the Standalone SDK. It depends on the device model and which firmware is installed in it.

In addition to that, the Connect function may return a false positive because it only establishes a TCP connection and it does not guarantee that the connection is valid.