August 2020
Reference Manual
L231040 Rev AD
13
Trim Digital-Analog-Converter (DAC):
These are factory set parameters used to
provide an accurate 4.000mA and 0.000mA.
This parameter should not be changed as
Magtech uses NIST traceable equipment to
calibrate our transmitters and only accredited
laboratories for the annual calibration of our
equipment. This menu will allow the user to
change the accuracy of the transmitter
output.
TrimDAC?
No
A current meter should be used to monitor the 4/20mA
when this function is selected.
Test Loop:
This function allows for direct control of the
Transmitter’s current output (mA) capability.
Simply enter into this menu and change the
current (mA) output as desired. This option
is excellent for plant startup verification.
TstLoop?
No
Exit:
This signifies the last menu before the main
screen. If the user desires go back through
the configuration menus then change the
“Yes” to “No” and review the configuration
again else press enter while the screen shows
“Yes” and return to the main screen.
Exit?
Yes
Exit to Displays
5.2 Features Description
Scrolling Option:
When choosing not to scroll the main menu the following
options can be chosen by pressing the up and down push
buttons.
Display?
Display?
Display?
Display?
Display?
Display?
Scroll
(or)
Level
(or)
Intrface
(or)
Temp
(or)
mA Out
(or)
%
Range
Rate of Change (RoC) Filter:
The RoC filter is a continuous monitor of how fast (the rate)
the level is rising and falling. It is also an excellent tool to
help eliminate any temporary spontaneous noise that may
be present in-field. For example, if the level in a tank cannot
rise or fall faster than 12.0 in/s then the setting for the RoC
filter should be set to 12.0 in/s or less to help filter/ignore
erroneous readings.
Offset:
The offset is a digital number that gets added to both the
LRV and URV to account for any distance below the sensor
probes measuring distance. For example if the offset is
changed from “0.00in” to “2.00in” the ‘Level’ on the main
screen will show “2.00in” at 4.00mA and the 20.00mA value
will simply have 2.00 inches added to it.
5.3 Advance Menus
There is an “advance” menu incorporated into the LTM-350
model. To access this menu press and hold the increment
( ) button first then while holding the increment button
press and hold the enter button for 3 seconds. A new menu
will appear on the LCD screen.
The following is a flow chart of the “advanced” menus
ComPort?
Serial
Yes No (Yes)
Active
Default?
Default?
Yes No (Yes)
Load Save (Load)
The “Scroll” option will vary depending on how many
outputs are configured.
The engineering units will change according to units
selected (i.e. cm/s).
The span will not change and the 4/20mA will not
shift from its original calibrated points. This offset value will
also add to the interface level when available.
