Nexcom NIO200 HAG, User Manual

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NIO200 HAG User Guide Page 57 of 120
7.6.1. Mapping Registers
The mapping area contains two sections listings the two different groups of registers: Input Registers
and Holding Registers.
The mapping between a register and a device variable is achieved by adding register line in the
appropriate section. Please note that mapping read-only variables to holding registers will not make
the variables themselves writable.
To add a register line:
1. In an empty edit box, type the parameters in the order and format indicated in the Help form:

start address - decimal integer, between 0 and 65535, representing the start
address of the Modbus register;



word count - decimal integer, between 1 and 125, representing the number of
16-bit modbus words allocated for this Wireless HART data element;



EUI-64 -
string of 16 hex digits, representing the 8 bytes of a device’s EUI-64
address;



register type: device_variable , gw_info or gw_code_word are the three
register types


supported;
When register type is “device
_
variable”, the following parameters must be specified:

the burst message you want to map;

device variable code;

device state - decimal integer, 0 and 2 with the following meaning:
o
0
– the Wireless Hart device variable is mapped onto the chunk of
registers, starting from address <start_addr>. The value should be
interpreted as 4 bytes float. Wireless Hart Communication errors (e.g.
device not joined) will make addressing these registers return the
MODBUS exception 0x04 (slave device failure);
o
2
– the Wireless Hart device variable is mapped onto the chunk of
registers, starting from address <start_addr>+1. The value should be
interpreted as 4 bytes float. At address <start_addr> there is a “device
state register” generated by the MODBUS server which reflects the