User Manual

2
Modbus Interface Specifications
Modbus Data Model
16
Building Technologies
A6V10316242_a_en
CPS Fire Safety
31.05.2019
CommandRange
Starting address of the set of Modbus Holding Registers associated to the
command objects.
Modifications to this field are ignored in the re-import. However, note that the base
addresses can be modified in the Composer configuration.
For each object, the current Modbus register address is determined by the sum of
Modbus BaseAddress and ModbusAddress.
ModbusAddress
Object offset address. This value can be changed in the CSV file and re-imported
to Composer.
CompactAddress
Starting address of the set of Modbus registers associated to the compact tables.
Modifications to this field are ignored in the re-import. However, note that the base
addresses can be modified in the Composer configuration.
For each object, the current Modbus register address is determined by the sum of
Modbus BaseAddress and ModbusAddress.
Base address for Bit Status Tables
The CSV file contains also the starting addresses of the Bit Status Tables (see Bit
Status Tables [➙ 24]).
Modifications to this field are ignored in the re-import. However, note that the base
addresses can be modified in the Composer configuration.
2.2.2 FS2xxx Register Map
Data Representation
The NK823x Modbus gateway can support multiple fire detection panels or
terminals (FC2xxx and FT2xxx). Each panel, terminal and gateway is represented
as a virtual Modbus device with its own Modbus Slave Address and a complete
register map. The map includes a number of sub-maps that represent the fire units,
and a general table for the gateway itself.
Fire Control Unit Representation
In the Modbus data representation, each panel is mapped as a separate Modbus
device with an individual address . The device address is defined at configuration
time.
A dedicated register sub-map is used for each panel, including six types of tables.
Namely:
 Summary tables
These are a set of word input registers including:
– The overall panel conditions (1 word register).
– The vitality counter (1 word register).
– As many as 525 data change flags (33 word registers) reporting any
modifications in the register area (the complete range of 65536 registers is
monitored).
 Status tables
These are word input registers reporting the conditions of all the mapped
objects. Each word corresponds with one object and is organized in two bytes: