ISCO 4210 - Programming the 4-20 Ma Outputs

4210 Flow Meter
Section 2 Programming
2-35
Instead, use the value that is the largest expected level for your
actual situation, even if this is less than the published
maximum.
The flow meter's internal resolution and its accuracy are based
on the value you enter for Maximum Head. The flow meter will
display:
2.7.6 Programming the 4-20
mA Outputs
If you turn on any of the 4-20 mA outputs (ANALOG OUTPUTS)
in step 1- Setup, programming the actual operation of the
output appears in step 2 - Select Flow Conversion.
Note
If you do not turn on the 4-20 mA output(s) in step 1, the
menus determining its (their) operation will not even appear
later in the program. If you need this function and cannot find
the appropriate menus in step 2, return to step 1, Setup and
check to see that you have not inadvertently switched the
option off.
For each 4-20 mA output port turned on, the flow meter will
request entry of the type of data that will drive the output, along
with minimum and maximum values. Here is an example of
what you might see for programming analog output 1.
TEMPERATURE, DISSOLVED OXYGEN, CONDUCTIVITY,
SPECIFIC CONDUCTANCE, SALINITY, and TOTAL DIS-
SOLVED SOLIDS may also appear as driving conditions.
The actual choices available to you will depend on what ports you
have turned on previously and what accessories (YSI, pH, DO
probes, rain gauge, etc.) you are using with your flow meter.
After you select one of the available choices, the flow meter will
request that you enter minimum and maximum values for that
choice:
Note that 4 MA in the second line of the display could also be 0
MA if that is what you selected for the current loop minimum in
Setup. The units available are the units of measure appropriate
for the option you selected; for example, feet or meters for level,
degrees F or C for temperature, mg./l for dissolved oxygen, etc.
After you have set the minimum value for the port, the flow
meter will request you to enter a value for full-scale, or 100%:
This value causes the port to transmit 100% or 20 mA. For
example, if the data type selected for this output were level, and
the unit is measuring level in a four-foot pipe, you would enter a
FLOW RATE AT MAXIMUM HEAD
X.XXX CFS (or other units of measure)
DATA TYPE FOR ANALOG OUTPUT 1
• (OFF)••(LEVEL)••(FLOW RATE)••(pH)•
ANALOG OUTPUT PORT 1
4 MA = X.X (units)
ANALOG OUTPUT PORT 1
20 MA = X.X (units)