SmartSwarm 300 Series
:
65
Str Value
val
This field is only relevant for Enum data types.
The Str Value field enables us to specify a string value that we
can use to add contextualized meaning to each relevant state
of bit-field data.
E.g. A 16 bit register may be represented by an Enum Data
Type. Each bit of the register might have a unique and
significant meaning. For each bit, there can be two possible
states: 0 or 1. We can create a row in the Register Table that
represents each bit in the Register (using Bit Offset and Width
fields). For each row, we can apply meaning:
Num Value = 0; Str Value = “Valve Closed”
Num Value = 1; Str Value = “Valve Open”
This Str Value field is not used for any algorithmic purpose
within the Device. It will become part of the enrichment-data
published for this register.
Table 21. Input Register and Holding Register editable fields
9.4.3.1.1 EXAMPLE USE OF ZERO VALUE AND SCALING
Condiser an example where a Modbus slave uses a 12-bit ADC to digitize a 4-20mA loop sensor which is measuring
temperature. The register value ranges from 819 to 4095, corresponding to a temperature range of 0 to +10°C.
The
enriched
value will be calculated as
(Modbus Register Value / Scaling) + Zero Value
It is recommended to draw the graph of input (raw Modbus register value) and output (enriched value) in order to
calculate the Scaling and Zero Value. Note that we assume that the relationship is linear.
