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Automatic Block Partition |
Starting with version 2.00, Modbus Driver now has a feature called Automatic Block Partition. With this feature, this Driver manages the division of blocks larger than protocol limits. Thus, users do not need to worry about exceeding the maximum limit for block size, because this Driver divides blocks in the correct sizes during communication with a device, if any Block Tag exceeds the maximum allowed size.
Starting with version 2.01, this Driver also supports Superblock Readings. With this feature enabled, users do not need to group variables into Block Tags aiming to improve performance, it is possible to use only Tags without degrading performance. And as the Superblock algorithm already considers the maximum block size allowed by the protocol, when this feature is used this Driver also does not need to use the Automatic Partition feature.
In cases when, due to device's specificity, as described on topic Superblock Reading (Grouping), it is not possible to enable the EnableReadGrouping property in E3 or Elipse Power, that is, the property that enables Superblocks, or if users are using the old Elipse SCADA, which does not support grouping (Superblocks, then they must use Automatic Block Partition to ignore protocol limits.
IMPORTANT |
Superblock grouping in E3 and Elipse Power, as well as this Driver's Automatic Block Partition, require that a device supports all limits established by standard Modbus. For more information, please check topic Maximum Limit for the Size of Blocks Supported by the Modbus Protocol. There are devices, however, that support lower limits. For this automatic block partition to work in these cases, as well as Superblock grouping, starting with version 2.03 this Driver allows customizing the maximum supported limit for PDU (Protocol Data Unit). To do so, on this Driver's configuration window, on the Modbus tab, enable the Customize Max. PDU Size option and configure the maximum size of bytes supported by this device for PDU. If a device has different limits for each function, it may be necessary to perform that grouping manually. For more information, please check topic Superblock Reading (Grouping). |
The article KB-23112 on Elipse Knowledgebase presents a summary of questions related to Tag grouping and Block resizing in this Driver, discussed here and in other topics. For more information, please check topics Superblock Reading (Grouping) and Optimization Tips.