Appendix 3.4 Result Update In Stream And Full Multiplex Modes - Hach BioTector B7000 User Manual

Appendix 3.4
As described above, the 4-20mA output channels in Stream and Full Multiplex Modes are not constant over
time, they change on periodical basis. The full set of outputted reaction results in a period of time is called
Results Sequence. When system completes the output of all measured reaction results, in other words the
whole results sequence, then all 4-20mA outputs is set to idle for a programmed period of time, which is
defined by the OUTPUT PERIOD parameter, in 4-20mA Program menu. This time represents the results
sequence output time.
This idle period can be interrupted if the system obtains a new result. If this happens, then a new results
sequence output is started. The minimal value of OUTPUT PERIOD depends on the type of 4-20mA Output
Mode and the system configuration. In other words, the parameter minimal value is defined by the time
needed to output the whole results sequence.
For example, if the system is configured to measure TIC, TOC and TN components from Stream 1, 2 and
Manual 1 valves and the SIGNAL HOLD TIME parameter is set to default 10s in 4-20mA Program menu:
In case of Stream Multiplex Mode, the parameter's minimal time can be found with the following formula:
Minimal OUTPUT PERIOD = [2 * (SIGNAL HOLD TIME) + 1s] * [Number of Streams]
In case of Full Multiplex Mode, the parameter's minimal time can be found with the following formula:
Minimal OUTPUT PERIOD = {[2 * (SIGNAL HOLD TIME) + 1s] * (Number of Results)]}* [Number of Streams]
Depending on the user application, because it may take a significant amount of time to complete a results
sequence output, when a new results is obtained while results sequence is outputted on 4-20mA output
channels, the system interrupts the outputting of the sequence after next result, outputs the new result and
continues in outputting the interrupted results sequence.
Both mechanisms, i.e. idle period cancellation and results sequence interruption, keeps the user device
updated with new reaction results within the shortest possible delay.
Result Update in Stream and Full Multiplex Modes
= [2 * 10 + 1] * 3
= 63s
= {[2 * 10 + 1] * 4} * 3
= 252s .
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