IM 50.560CA UA (B/4-03)
59
DEPOLOX
®
3
PLUS
RESIDUAL ANALYZER
3.7.4.1
Description of the Bytes of the Frames
•
Synchronization bytes: Used for the synchronization of the user units
to the others.
•
Start byte (SB): Marks the begin of a frame.
The value depends on the type of the frame:
Request frame
10H
Set frame
68H
Answer frame
68H
Positive confirmation
A2H
Negative confirmation
DCH
•
Slave address: To every module in the RS485 bus a special bus ad-
dress is allocated (slave address). The address can be a number be-
tween 0 and 31 Dec.
NOTE: The DEPOLOX 3
plus
module uses up to two bus addresses
because of the two-fold function of the module (Cl
2
measurement, pH
or fluoride measurement).
•
Destination address: Determines the transmission variable in the ad-
dress reference list, that is to be read or written.
•
Check byte: Determines the type of information to be read from the
slave. Also the data format is defined.
Data format of the check byte (Bit 0 through 3):
Bit (3210)
Dez.
Format:
0000
0
Default (to address reference list)
0001
1
Default (to address reference list)
0010
2
Boolean
0011
3
Boolean
0100
4
unsigned Character
0101
5
signed Character
0110
6
unsigned Integer
0111
7
signed Integer
1000
8
unsigned long Integer
1001
9
signed long Integer
1010
10
Floating Point
1011
11
Floating Point
1100
12
ASCII
