Using the CFT34A transmitter’s local display, press the Right arrow key (>) and keep it pressed until you see “Release key now” on the screen. Once you release the key, the display will read "quick setup".
Press the down arrow key two times so that "Setup" is shown on the screen, then press the right arrow key (>). Now you have entered the Setup menu. Press the right arrow key (>) to enter the Process Input menu. Use the down arrow key to navigate this menu and go to parameter C1.1.4 Flow direction. Configure this parameter for Forwards.
PATH: Process Input > Flow Direction > Forwards (according to the arrow on the flow sensor).
Once you have set the value of Flow Direction, back out of the Process Input menu by pressing the return key (⏎), until you see “Setup” again on the screen. Press the down arrow key to go to “I/O”. Press the right arrow key again.
The CFT34A transmitter can have multiple analog outputs, depending on what is purchased. Identify which of the Analog Outputs available in your device you will be using. Now navigate the I/O menu until finding the Current Output terminal you want to use. Press the right arrow key to enter the menu
PATH: Setup > I/O > Current Out X, with X = A, B, or C output terminals where the analog output is located.
1.SPLIT mA RANGE CONFIGURATION
The following are the parameters you will need to configure for a split range analog output:
C2._.2 Range
C2._.5 Polarity
C2._.6 Current Span
C2._.7 Range 0%...100%
1.1 Symmetric
Example: -150 GPM to +150 GPM
C2._.2 Range = 0 … 150 gal/min
C2._.5 Polarity = Both Polarities
C2._.6 Current Span = custom
C2._.7 Range 0%...100% = 12 – 20 mA
In this example, the negative/reverse flow will be equals to 4 – 12 mA (-150 GPM – 0), and the positive/forward flow (0 – 150GPM) will be equals to 12 – 20 mA.
1.2. Asymmetric
Example: -50 GPM to +150 GPM
C2._.2 Range = 0 … 150 gal/min
C2._.5 Polarity = Both Polarities
C2._.6 Current Span = custom
C2._.7 Range 0%...100% = 8 – 20 mA
In this example, the negative/reverse flow will be 4 – 8 mA (-50 GPM – 0), and the positive/forward flow (0 – 150GPM) will be 8 – 20 mA.
To calculate the mA value equivalent to your 0% value in parameter C2._.7, open the spreadsheet attached to this article, then enter your minimum and maximum flow values in the green cells (full scale). When done, the yellow cell value is what you should enter into parameter C2._.7 as the ZERO Flow mA Value.
2. FULL mA RANGE CONFIGURATION
As the full 4 – 20 mA range will be used for both Forward and Reverse flow, the analog output will need to be used in combination with a status output of the transmitter, to identify the flow direction being output by the CFT34A.
Identify the terminals’ location of your pulse output, then go to Setup > I/O > Hardware > Terminals X (with X = A, B, or D output terminals where the pulse output is located) and configure it for “Status Output”. Press the return key (⏎) to go back to the I/O menu and navigate using the down arrow key to go to the Current Out and Status Output submenus.
The following are the parameters you will need to configure in the Current Output submenu for a 4 -20 mA full range analog output in both forward and reverse flow. A full range of -150 …. 150 GPM is being used as an example
C2._.2 Range = 0 … 150 gal/min
C2._.5 Polarity = Both Polarities
C2._.6 Current Span = 4-20mA
In the Status Output menu corresponding to your pulse output terminals, configure parameter C2._.1 Mode to “Flow Polarity”.
Parameter C2._.3 Invert Signal in the Status Output menu will determine if your status output terminals are open or closed during forward flow.
Once you have finished with your configuration, carefully press the Return key (⏎) repeatedly to go back to Measure mode. At the prompt “Save Configuration?” make sure that YES is selected, and then say yes by pressing the Return key (⏎) again:
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