45
Conditions
Non-linear
input
Linear input
DP = 0
Linear input
DP = 1
Linear input
DP = 2
Linear input
DP = 3
Scale low
-1999.9
-19999
-1999.9
-199.99
-19.999
Scale high
4553.6
45536
4553.6
455.36
45.536
For ETR-9100, ETR-8100 and ETR-4100
7-4 Data Conversion
The word data are regarded as unsigned (positive) data in the Modbus message. However, the actual value of the
parameter may be negative value with decimal point. The high/low scale values for each parameter are used for the
purpose of such conversion.
Let M = Value of Modbus message
A = Actual value of the parameter
SL = Scale low value of the parameter
SH = Scale high value of the parameter
The conversion formulas are as follows:
M =
65535
SH-SL
( A SL)
A =
65535
SH-SL
M + SL
7-5 Communication Examples :
Example 1: Down load the default values via the programming port
The programming port can perform Modbus communications regardless of the incorrect setup values of address,
baud, parity, stop bit etc. It is especially useful during the first time configuration for the controller. The host must be
set with 9600 baud rate, 8 data bits, even parity and 1 stop bit.
The Modbus message frame with hexadecimal values is shown as follows:
