Ultrasonic Level Transmitter
ULM84 Series User Manual
Dec.2020
Page 15 of 21
FAHM Co.
Industrial Automation
Doc. ULM84 Rev.99-12
Figure 21- Device Terminal, as seen as the back cover is opened
Define Liquid Level to Activate Low-Low Alarm (
P23 Alarm Limit LO-LO
)
The user can set a value commensurate with the level at which he expects this alarm to work; If the fluid
level is lower than the above level, this alarm will work; To return it to normal, the fluid level must be higher
than the value set in the "P16 Relay Buffer" menu.
Also, by opening the back cover of the equipment, the user can see the terminals of this alarm as shown in
Figure 21.
Determine the buffer level relative to the excitation state to return the alarm to normal (
P24
Alarm Buffer
)
To prevent the alarms from activating and normalizing continuously, this value is adjusted so that the
condition for the High and High-High alarms to return to normal is that the fluid level is lower than the value
set in this menu than the level set for activating the alarms; and the condition for the Low and Low-Low
alarms to return to normal is that the fluid level is higher than the value set in this menu than the level set for
activating the alarms.
11. Transmitter’s Advanced Settings (Password: 00101)
In this section, the advanced settings of the transmitter will be fully described. To enter the advanced
settings of the transmitter after pressing the ENT key, the Password page will open with the default
password "00000". By changing this number to "00101" and pressing the ENT key, we will enter the
advanced settings of the transmitter.
Define Damping Time of the Transmitter (
P40 Damping Time
)
Low damping time increases the sensitivity of the transmitter and reflects the smallest changes in input at
the output current as well as the displayed level; Conversely, if this large value is selected, the value
displayed on the display and the output of the current will be more stable and will fluctuate less. By default,
this value is set to 10 seconds.
Define Alarm State (
P41 Alarm Output
)
There are three ways to alert the alarm; these choices and the performance of each are listed in the table
below
.
Table 7 - The three alarm states and their operation
Selected State
Function
High
When the alarm is activated, the output current of the transmitter will be 21.75 mA
Low
When the alarm is activated, the output current of the transmitter will be 3.75 mA
Last
When the alarm is activated, the output shows the last valid value
