The menu is the main loop of the sample client, so you will have to find the piece of code that calls it, if you wish to remove it. Unfortunately, I don’t have the code with me right now, but it should be very obvious. Start to look for it at the main() function.

Hi,

I cannot personally say regarding the C SDK specifics, but I can answer something in general at least for now.

30 Subscriptions sound a really big number, do you really need that much? Typically applications use like 1 or 2. Note that a single Subscription can have multiple MonitoredItems.

Anyway, an OPC UA Server can impose limits on these, some servers might support like 500 Subscriptions per sessions, some only 1-2 or some maybe none (but they might be some Nano profile devices that only support e.g. the Read service), thus it is not possible to answer “what is max number of subscriptions”, since it depends on the server you are connecting to. Thus please check the server’s settings for those limits.

Also the number of items per subscription might be limited by the server. Typical defaults in the samples of the https://www.prosysopc.com/products/opc-ua-java-sdk/ server side currently is 500 Sessions, 50 Subscription per Session and 1000 items per Subscription. Though, the limits might be different per the applications using the SDK since it would depend e.g. on the hardware they are run and to what use-case they are intended.