Direct Mode - Hach BioTector B7000 User Manual

Appendix 3
BioTector features three different 4-20mA output operation modes programmable in 4-20mA Program menu:
1) Direct Mode – simple mode
2) Stream Multiplex Mode – more complex than Direct Mode, but significantly reduces number of
necessary output channels
3) Full Multiplex Mode – more complex than Stream Multiplex Mode, but can be configured to output
system results from any stream via only 4 channels
The reason to extend the system 4-20mA mechanism with Stream and Full Multiplex Mode was to overcome
the problem of limited number of 4-20mA channels in case of systems where multiple measured components
(TIC, TOC, VOC, TC, TN etc.) on different streams are measured.
The usage of Stream and Full Multiplex Mode requires a small amount of processing on the user's side
(usually via PLC), but can effectively reduce number of necessary output lines and / or extend system output
capability.
Appendix 3.1
4 - 2 0 m A P R O G R A M
1 < O U T P U T
2 C H A N N E L
3
4 C H A N N E L
5
6 C H A N N E L
7
8 C H A N N E L
9
1 0 C H A N N E L
1 1
▼
The BioTector's 4-20mA output Direct Mode is the simplest output mode, where each output channel is
assigned a set of parameters (stream type, reaction result, range and result type). In this mode, 4-20mA
output channels are updated only if there a new reaction result calculated in the system which exactly
matches the channels settings or if in case of system fault occurrence. The disadvantage of this operation
mode is that there is a need for dedicated output channel for each reaction result. The typical connection
between the BioTector and the user device is shown in figure A3.1.
Figure A3.1 BioTector 4-20mA output signals in Direct Mode
BioTector
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
4-20mA READ relay
BioTector 4-20mA Output Modes

Direct Mode

M O D E
1
2
3
4
5
Direct Mode
Stream1, Instantaneous TOC, 100mgC/l
Stream1, Instantaneous TIC, 70mgC/l
Stream2, Instantaneous TOC, 500mgC/l
Stream3, Average TIC, 250mgC/l
0 9 : 1 7 : 2 8 1 2 - 0 9 - 0 2
D I R E C T
S T R E A M 1 ,
5 0 0 m g C / l ,
S T R E A M 1 ,
1 0 0 m g N / l ,
- - - ,
1 0 m g C / l ,
- - - ,
5 0 0 m g C / l ,
- - - ,
5 0 0 m g C / l ,
T O C
I N S T
T N
A V R G
V O C
I N S T
T I C
I N S T
V O C
A V R G
User Device
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