Festo SFC-LAC CO Series, Руководство пользователя

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C. Object directory DS204 and CI
C−45
Festo P.BE−SFC−LAC−CO−EN en 0708NH
Note
The following applies when writing the objects:
Discrete values (values from a value list):
An invalid value will not be accepted, the previously
valid value will be retained.
Continuous values (e. g. lengths, speeds):
A non−permitted value will be limited up to the next
permitted minimum or maximum value.
Note
Direct transfer of values using CI commands via the serial
interface takes place in
increments and requires conver
sion.
All parameters are always saved in increments in the
controller and are not converted into the relevant
measuring system until they are written or downloaded.
Further information on converting can be found in
appendixA.3.
All values are transferred in hexadecimal figures; 1 character
represents 4 bits; it is known as a tetrad <Tn>. The first tetrad
transferred contains the higher−value bits of the value. Gen
erally: Tetrad <Tn> contains the bits b
n
... b
n+3
Example: UINT8
Dec 26
Hex 1 A
Bin 0 0 0 1 1 0 1 0
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
Tetrad T
4
Tetrad T
0