4230 Flow Meter
Section 2 Programming
2-18
current loops are brought out to a 6-pin M/S connector in the slot
where the Modem connector is usually mounted. Additional
information for the internal analog output board, including spec-
ifications for the loops, is found in Section 4.
The following menus determine the behavior of the 4-20 mA
current outputs. If you select ANALOG OUTPUT (another term
for the 4-20 mA Output) and the flow meter is equipped with the
optional internal board or the 4-20 mA external accessory has
been turned on, RANGE, SMOOTHING, and MANUAL
CONTROL will appear:
CAUTION
Each 4-20 mA output represents a constant drain on the flow
meter of at least 16 mA whether activated or not. While 4-20
mA applications are generally made in installations with com-
mercial power available, Isco suggests the following for those
who have a 4-20 mA output in a battery-powered installation.
Use with battery powered flow meters only if:
• the battery is continuously on charge (for example with
a Solar Panel Battery Charger)
• the battery is very large, such as a deep-cycle or marine
type battery, or an Isco 35 Ampere-hour lead-acid
battery.
• using only one 4-20 mA output.
Keep in mind that programming choices also affect power con-
sumption. Use “minimum” settings on the flow meter wherever
possible. (See Section 1, Table 1-8.)
Even with these circumstances, you may expect significantly
shorter charge life from your battery. To determine the effect of
this extra current draw on battery life, please refer to the section
How to Make Battery Calculations, at the end of Section 1.
Programming for the conditions and values that determine the
operation of the 4-20 mA loop (or loops) is done in step 2.
Note
If you know for certain that you have the proper installed hard-
ware for internal 4-20 mA outputs and you do not see the
proper displays, return to the “normal” flow meter display and
press 4 - 2 - 0.
ANALOG OUTPUT
• EXTERNAL 4-20 MA • • (RANGE) • • (SMOOTHING) • •
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