Modbus Integration (MO - subsystem-specific extension)

Data type defines the data type for encoding the subsystem-specific data type.

16 bit integer data formats with Registers:

Encoding format

Description

Byte order

U16-B
U16-L

unsigned 16-bit; big-endian
unsigned 16-bit; little-endian

bb aa
aa bb

"Bit-Offset" defines an offset in reading bitset of data (Coils, Discrete Inputs). This allows to support mass manipulation/correction of data point addresses.

-1

0

100

"Number of bits" defines the size of the bitset (unsigned).

Range: 2…16; 16:=U16-B and U16-L

"Heartbeat timers" defines the heartbeat timer to be used to update the subsystem-specific data point if there is no change of "Present value" for a longer time.

The interval values for H1, H2 can be configured in the Fieldbus-Management-Object.
Heartbeat timers are independent from COV triggered updates.
Heartbeat timers and Polling timers are independent from each other.

None

No updates of the subsystem-specific data point.

H1

Highest priority. Typical interval value: 5s…60s.

H2

Low priority. Typical interval value: minutes ... hours.

"Mapping table" defines the mapping of "Present value" to a subsystem-specific bitset data which corresponds to the array index of "Mapping table". Mapping table

Constraint on Actual-Length:
Mapping table, Number of states and State text require the same length.

Example:
Present value=1 => Mapping table[1]:=0x0000 => 0x0000
Present value=2 => Mapping table[2]:=0x0001 => 0x0001

"Min repetition time" defines the minimum wait time between two consecutive updates of the Modbus data point.

"Min repetition time" is used to limit the network traffic in case of excessive changes of "Present value".

"Min repetition time" may be zero to allow fast updates of MODBUS data points.