Teledyne 4250 Installation And Operation Manual page 82

4250 Flow Meter
Section 2 Programming
2-54
After you have determined what condition will signal the
sampler and under what circumstances, the following menu will
appear:
SELECT OPERATOR
• DONE • • OR • • AND •
This step allows you to trigger the sampler from a single con-
dition or from two conditions. Suppose you wanted to trigger the
sampler from only one condition and that condition was level.
You would select level as the condition, and then identify what
change in level would be the trigger. Then you would select
DONE for the SELECT OPERATOR step. Selection of DONE
will advance the flow meter to the next program step. Selection of
OR or AND will allow you to select another condition, and then
determine whether both conditions are necessary for enabling
(AND) or whether either condition will enable the sampler (OR).
If you select FLOW RATE:
FLOW RATE
• GREATER THAN • • LESS THAN • • RATE OF CHANGE •
You would select one of these options, and then enter a value, as
for LEVEL, previously.
The rest of the menus will appear the same as they did for
LEVEL and FLOW RATE. D. O., pH, TEMPERATURE, and
RAINFALL all require activation in step 1 and use of the appro-
priate sensor. Only one parameter condition (pH, D. O.) can be
measured by the flow meter at a time. pH and D. O. will not
appear on the display at the same time.
It is possible to program the sampler enable option so that it
operates in two different modes, latching and non-latching.
To explain this, in the non-latching mode the sampler will be
enabled only as long as the condition that caused the enabling
remains outside of "normal." If the enabling condition returns to
"normal," the sampler enable will turn off until the next time the
condition goes outside of "normal."
In the latching mode, the sampler will be enabled the first time
the condition goes outside of normal and the sampler will stay
enabled regardless of any later changes to the enabling condition.
If this is the case, the following menu will allow you to reset the
sampler enable feature. Note that this menu will not appear
unless the condition necessary to enable the sampler has been
met and the sampler is currently enabled.
WHEN ENABLE CONDITION IS NO LONGER MET
• DISABLE SAMPLER • • KEEP ENABLED •
Or:
ENABLE CURRENTLY LATCHED, RESET?
• NO • • YES •