31.6.Advanced options - optimizations
mySCADA in default settings is highly optimized for optimal speed and memory requirements of typical hardware. However, further optimizations can be made for speeding up sensitive applications.
Separate Writes Optimization
When a connection to PLC is defined, mySCADA will use one socket for communication with this PLC. If there are write requests in the queue, mySCADA will process them before it starts reading. If there is a large number of write requests, the read period will increase accordingly. To eliminate this behavior, mySCADA can set write requests to PLC on an independent channel (e.g. New socket connection). To do so, enable “Separate Writes” in the Connection definition.
Optimization Window – Block Read Optimization
mySCADA is using optimized data read and writing from PLCs; this is achieved by combining all read/write requests for the given PLC into blocks of data to be read. Each connection has the maximum size of the data block set to default values. You can override this value by changing the size of the data block to be read at once. There might be two reasons to do so:
- Your PLC is not able to provide data in such a large block; in that case, you must decrease the Optimization Window size
- Your PLC can provide data in a larger block than selected, if you increase the Optimization Windows size, you can achieve higher read speeds from your PLC.
Multiple Channels Optimization
As already stated previously, mySCADA uses one communication link to the PLC. If there are multiple, fast-changing requests (for example, a high number of users changing views), mySCADA will optimize communication data quite often. To eliminate this, you can create multiple connections to the same PLC. For example, you can create one connection for CAS Alarms, one for data-logs, and one for views. This way mySCADA will use three simultaneous connections to the PLC. As CAS Alarms and data-log requests don’t change, mySCADA does not have to optimize the data blocks for these two connections. Only the third connection will have to be optimized. This way high-speed data exchanged with PLC can be achieved.
To use multiple channel optimization, your PLC must allow for enough simultaneous connections.
