Lockout Feature - GPI GM Serie Guía De Operación

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. Re-
lease them when the light blinks.
NOTE: The length of time between "button press" and
"light blink" depends on the transmitter response
time. The maximum 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 procedure, it should be registering at or very
near 20 mA (within the resolution specifications for
the present conditions).
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. Select 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 pushbut-
tons on the transmitter. You should be able to see the
indicator light.
To lock the transmitter, use the pushbuttons to enter
the following 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 following 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 pushbut-
tons 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 de-
vice like the GPI transmitter is not obtainable. That's
because the current loop powers the transmitter,
and its operating current 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
pushbuttons 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.
2. Set the 20 mA endpoint as described above under
4-20 mA calibration.
3. The special 0-20 mode will remain in effect until a new
4 mA endpoint is established in the usual way.
Auxiliary 0-5 VDC
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