14
4. All enabled units-of-measure remain visible and selectable
– the entered correction will be applied to all enabled units.
5. To return to factory calibration (FAC), press and hold both
CALIBRATE and DISPLAY buttons for about 3 seconds until
FAcCAL is displayed. Then release buttons. Unit should
return to normal operation and FAC icon is visible.
Setting 4-20 mA Endpoints
The 4-20 mA endpoint settings are independent from the display
calibration. If you reset the response time you MUST reset the
4-20 mA endpoints.
All units are shipped with the preset at: Response time = 0.7
seconds
Any new values you set for these items are automatically saved
when the transmitter is powered down, and automatically re-
stored the next time power is applied.
Procedure
Before you start, the fluid pumping system should be ready to
make two simple calibrating runs, first at the lowest anticipated
flowrate, and then the second at the highest anticipated flowrate.
Position yourself so you can easily operate the transmitter’s
pushbuttons. You should be able to see the indicator light (the
small window beside the “4” button).
Setting the Low (4 mA) Endpoint:
To set 4 mA at zero flow, go to step 3. Otherwise follow
steps 1, 2 and 3:
1. Start the fluid pumping system. Set it for steady flow at
the lowest anticipated rate (or the rate at which you want
a “minimum” indication).
2. Wait while the fluid flow is uninterrupted for at least 10
seconds.
3. While watching the transmitter’s indicating light, press and
hold both its “SET” and “4” buttons. Release them when
the light blinks.
NOTE: The length of time between “button press” and “light
blink” depends on the transmitter response time. The maxi-
mum is 5.2 seconds. If you can’t see the indicator light (if
you’re outdoors in bright light), you can safely just count
to 10 while holding the pushbuttons.
NOTE: After setting the minimum, the loop current should be
registering at or near 4 mA. Don’t worry if it’s not exact, it
will be correct after setting the high (20 mA) endpoint.
Setting the High (20 mA) Endpoint
1. Start the fluid pumping system. Set it for steady flow at the
highest anticipated rate (or the rate at which you want a
“maximum” indication).
2. Wait while the fluid flow is uninterrupted for at least 10
seconds.
NOTE: If you observe the current loop after completing the pro-
cedure, it should be registering at or very near 20 mA (within
the resolution specifications for the present conditions).
OPERATION – 4-20 mA
3. While watching the transmitter’s indicating light, press and
hold both its “SET” and “20” buttons. Release them when
the light blinks.
NOTE: During the high and low setpoint procedure, if the new
settings are very different from the previous settings, it is
possible to reverse the 4 mA and 20 mA setpoints so that
the 4 mA frequency is
higher
than the 20 mA frequency. The
situation corrects itself after you complete both setpoints. If
the new settings are close to the previous settings, you may
safely set either the low and high settings independently.
Lockout Feature
This transmitter includes a user selectable lockout feature. Se-
lect the feature after setting the 4 and 20 mA endpoints during
initial use. The lockout feature prevents tampering with the 4
and 20 mA settings on the transmitter.
Before activating the lockout feature make sure there is no signal
being received by the transmitter. If signal is being received,
deactivate it by one of the following methods:
• Stop the flow through the line that is being recorded.
• Disconnect the output device on the flowmeter.
Locking / Unlocking the Transmitter
Position yourself so you can easily operate the pushbuttons on
the transmitter. You should be able to see the indicator light.
To
lock the transmitter, use the pushbuttons to enter the follow-
ing sequence with a brief pause between each button press:
20 – 20 – 20 – SET. The indicator light will blink twice to indicate
the unit is locked.
To
unlock the transmitter, use the pushbuttons to enter the fol-
lowing sequence with a brief pause between each button press:
4 – 4 – 4 – SET. The indicator light will blink once to indicate
the unit is unlocked.
Checking the Status of the Lockout Feature
To check the status of the transmitter, use the pushbuttons to
enter the following sequence with a brief pause between each
button press: SET – 4 – 20 – SET. The indicator light will blink
once if unlocked or twice if locked.
Optional 0-20 mA Mode
A few current loop systems use 0-20 mA output. The input signal
frequency of “0” produces an output analog signal of “0” with
direct proportionality and no offset.
NOTE: A true loop current of “0” in a loop powered device like
the GPI transmitter is not obtainable. That’s because the
current loop powers the transmitter, and its operating cur-
rent is non-zero even at zero frequency input. In 0-20 mode,
the GPI Transmitter’s loop current will drop to as near zero
as possible at zero input, in most units between 1 and 2 mA.
Procedure
1. To enter 0-20 mode, simply press and hold all three push-
buttons simultaneously (4, SET, and 20) at any flowrate.
Continue holding until the indicator light blinks (light will
blink in up to 5 seconds) and release all buttons. This sets
the LOW END calibration point to zero/zero.
Summary of Contents for GA
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