PRON NA60-MB0
Version 3.50
PRON NA60-MB0 Remote Setting Manual
Page: 6 of 59
2 Logical organization of the protection’s data
Each TPR has some data that can be read and/or written. These data are grouped in 4 data table.
Data with 1 bit of information (e.g. the state of an output), can be placed in the Discrete Inputs table or in the Coils
table, while data with more than 1 bit of information (e.g. the value of a current), can be placed in the Register
table, sometimes fitting more than one register as described in the following example.
1x, Discrete Input
3x, Input Registers
n°
var
n°
var
6
I> Start
157
Power frequeny
7
I> Trip
158
Phase current IL1 value – Word L
8
I> Block1
159
Phase current IL1 value – Word H
160
Phase current IL2 value – Word L
161
Phase current IL2 value – Word H
Table 4. Example of data structures
Example: let’s read the value of the variable ”I> Start”. This variable is the first one in the Discrete Input data table.
To read this kind of data the Modbus function 0x02 has to be used. As described in the standard the Modbus
address to access the data is given by IDX-1 = 5 in this case.
To read the data from the Slave address 1 the next request has to be sent:
01 02 00 05 00 01 -
-
TX
S
F
ADR
DIM
CRC
2.1 Basic Data Type
In this chapter all the basic TPR data type and their relationship with the Modbus data type will be described.
2.1.1 BIT
Description:
Variable with 1 bit of information.
Relationship with Modbus:
The information corresponds to the least significant bit (lsb) of the first data byte addressed in the query.