Emotron FDU40-003 - Functional Description

60 Serial communication Emotron AB 01-3694-01r2
10.3 Start and stop commands
Set start and stop commands via serial communication.
10.4 Reference signal
The reference value is set in modbus number 42905. 0-4000
h corresponds to 0-100% of actual reference value.
10.5 Description of the EInt
formats
Modbus parameters can have different formats e.g. a stand-
ard unsigned/signed integer, or eint. EInt, which is described
below. All parameters written to a register may be rounded
to the number of significant digits used in the internal sys-
tem.
If a parameter is in Eint format, the 16 bit number should
be interpreted like this:
F EEEE MMMMMMMMMMM
FFormat bit:
0=Unsinged integer mode,
1=Eint mode
EEEE 2 complement signed
exponent
MMMMMMMMMMM 2 complement signed
mantissa.
If the format bit is 0, then can a positive number 0-32767 be
represented by bit 0-14.
If the format bit is 1, then is the number interpreted as this:
Value = M * 10^E
Example
If you write the value 1004 to a register and this register has
3 significant digits, it will be stored as 1000.
In the Emotron floating point format (F=1), one 16-bit
word is used to represent large (or very small numbers) with
3 significant digits.
If data is read or written as a fixed point (i.e. no decimals)
number between 0-32767, the Emotron 15-bit fixed point
format (F=0) may be used.
F=Format. 1=Emotron floating point format, 0=15 bit
Emotron 15-bit fixed point format.
The matrix below describes the contents of the 16-bit word
for the two different EInt formats:
Example of Emotron floating point format
A signed number should be represented as a two comple-
ment binary number, like below:
Value Binary
The value represented by the EInt floating point format is
m·10
e
.
To convert a value from the EInt floating point format to a
floating point value, use the formula above.
To convert a floating point value to the EInt floating point
format, see the code float_to_eint below.
Example
The number 1.23 would be represented by this in EInt
The value is then 123x10
-2
= 1.23
Modbus/DeviceNet
Instance number
Function
42901 0 Reset
42902 1
Run, active together with
either RunR or RunL to per-
form start.
42903 2 RunR
42904 3 RunL
e3-e0 4-bit signed exponent.
-8..+7 (binary 1000 .. 0111)
m10-m0 11-bit signed mantissa.
-1024..+1023 (binary
10000000000..01111111111)
-8 1000
-7 1001
..
-2 1110
-1 1111
0 0000
1 0001
2 0010
..
6 0110
7 0111
F EEEE MMMMMMMMMMM
1 1110 00001111011
F=1 -> Eint
E=-2
M=123
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
F=1 e3 e2 e1 e0 m10 m9 m8 m7 m6 m5 m4 m3 m2 m1 m0
F=0 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0