Datasheet

Modbus TCP Communication HIMA H41q/H51q ↔
↔↔
↔ Emerson DeltaV
9
As an example the dataset configuration for output of real values is shown in Figure 2.8. Using the
output read back option on the general tab requires definition the corresponding variables in the
H41q/H51q PES as “Import/Export”. The dataset is assigned a dataset tag with which it can be
browsed out of the application logic of the DeltaV control modules.
The demonstration application on which this Application Note is based utilizes reading and writing
communication data as Boolean, unsigned integer and real values. The necessary settings for these
data types in the datasets are shown in
Special Data
Data Type DeltaV Data Type Device Data Type
Data 1 Data 2
Boolean Boolean with status 0 0 0
Unsigned Integer 16 bit uint w/Status 3 0 0
Real Floating point with status 3 1 2
Table 2.2: Dataset Configuration settings
2.3.3 Application Software Configuration
Modbus TCP communication data can be referenced for input or output in DeltaV control modules via
external reference parameters. When browsed the reference path looks like:
“TCP_REAL_OUT01/R307”. The first part of the reference before the slash is the tag name while the
latter part describes the register address.
Note 7:
There is an offset of one register address between H41q/H51q and DeltaV. The
register number in a reference path like “TCP_REAL_OUT01/R307” connects to the
register address 306 in H41q/H51q. However the “Data start address” on the PLC tab
of the dataset properties refers to the correct address (see Figure 2.8) but the first
created register within this dataset gets address 307.
This communication data can as well be referenced directly in analogue (AI) or discrete (DI) input
blocks.
Communication data also consumes I/O licenses in the DeltaV system. Therefore binary input and
output data should be bundled and unbundled to unsigned integer variables in DeltaV using “Binary
Fan In” and “Binary Fan Out” function blocks like shown in Figure 2.9.
Figure 2.9: Unbundling Binary Input Data