Teledyne 4220 installation and operation guide Programming the 4-20 mA Outputs

4220 Flow Meter

Section 2 Programming

The flow meter's internal resolution and its accuracy are based on the value you enter for Maximum Head. The flow meter will display:

FLOW RATE AT MAXIMUM HEAD

X.XXX CFS (or other units of measure)

Programming the 4-20 mA Outputs

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.

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. 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.

DATA TYPE FOR ANALOG OUTPUT 1

• (OFF)••(LEVEL)••(FLOW RATE)••(VELOCITY)••(pH)•

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 choices available to you, the flow meter will request that you enter minimum and maximum values for that choice:

ANALOG OUTPUT PORT 1

4MA = X.X (units)

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 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%:

ANALOG OUTPUT PORT 1

20 MA = X.X (units)

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 full-scale value of four feet. If the actual level reading is cur- rently two feet, the analog output would read 12 mA (50% if the 4-20mA current range is selected) or 10 mA (50% if the 0-20 mA

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