Like other Modbus-based drivers, TBox can scan data in one operation from multiple points organized into blocks. Usage of blocks in TBox has some differences from the Modbus standard.
When commissioning TBox RTUs, take care to configure points in blocks to increase the efficiency of data access. You need to do this in the TBox configuration software. Configure the Geo SCADA Expert database to match the Modbus addresses used in the blocks.
Points that are formed into blocks have consecutive Modbus addresses. The TBox driver is unable to scan across a gap in the addresses. This is a limitation of the TComm protocol.
The number of addresses for each digital point reflects the data type of each point (one address for a 1-bit point, two consecutive addresses for a 2-bit point and three consecutive addresses for a 3-bit point).
A maximum of 1600 1-bit points can be included in a single block. The number of points is reduced if the block includes 2- or 3-bit digital points. A block can include a maximum of 125 16-bit or 62 32-bit points.
When points are included in a block and have different read rates, the points in the block are read at the fastest rate specified for any point in the block (see Adjust the Configuration of any Points that Cause a High Load).