ABB RET 54 Series Technical Reference Manual, General page 82

RET 54_
82
Transformer Terminal
Technical Reference Manual, General
Fig. 5.1.13.11.-1Principle of connecting LON inputs and outputs to logic functions
of the transformer terminal
Each SNVT_state network variable can be used to communicate either an integer
value in the range of 0-65535 or up to 16 Boolean values as a binary coded number.
The type conversion function BOOL2INT is useful for packing and INT2BOOL for
unpacking the binary coded variables. Each bit indicates the state of the Boolean
value with, for example, the following interpretations:
0 1
off on
inactive active
disabled enabled
low high
false true
normal alarm
The communication inputs and outputs are seen in the relay configuration tool as
global variables:
category
communication inputs (sinks) COMM_INx
communication outputs
(sources)
where x is a number from 1 to 32. Similar names are used in the LON Network Tool.
The basic operation principle is that every time the output value is changed by the
configuration, the new value is propagated automatically over the LON network
to all communication inputs that are bound to the output. The network variable
connection can be from a single source to one or many sinks. An output can also
be unbound, i.e. it is not transmitted to LON network at all. Also an input can be
unbound, i.e. no updates will be accepted to this input.
name datatype
UINT
COMM_INxIV BOOL
COMM_OUTx UINT
1MRS755225
lonlog_b
purpose
input value
input invalidity flag, FALSE
indicates a valid state
output value