asyn-port-driver

To implement an EPICS asynPortDriver device driver, define typed parameters with createParam(), override virtual read/write methods, and manage update propagation through callParamCallbacks() for I/O Intr scanning and synchronous I/O.

For array parameters in asyn, call explicit doCallbacksXxxArray() functions to publish updates, while using callParamCallbacks() for scalar and string parameters to ensure correct I/O Intr scanning propagation.

Structure a polling thread in an asynPortDriver subclass by using thread-safe background polling with proper lock() and unlock() calls to protect parameter access and ensure update propagation across scalar, string, and array parameters.

Select interfaceMask and interruptMask in EPICS asyn parameters to define which asyn interfaces records use for read/write operations and which support I/O Intr callbacks, ensuring correct mapping to record INP/OUT links.

Yes, you need iocsh and DBD registration to deploy an asynPortDriver in an EPICS IOC, requiring an iocsh configure function and a DBD registrar entry to properly load and initialize the driver.

Handle alarms and tracing in an EPICS asyn device driver by setting parameter status and alarm severity via setParamStatus(), using asynPrint for tracing, and implementing shutdown and destructor patterns for clean stopping.