DMS-20LCD-4/20P-C Murata Power Solutions Inc, DMS-20LCD-4/20P-C Datasheet - Page 3

• Manufacturer Part Number: DMS-20LCD-4/20P-C
• Description: Current Meter
• Manufacturer: Murata Power Solutions Inc

Specifications of DMS-20LCD-4/20P-C

• No. Of Digits / Alpha: 3-1/2
• Meter Function: Loop-Powered
• Meter Range: 4-20 MA
• Digit Height: 9.4mm
• Supply Voltage Range: 1.8-2 V
• Operating Temperature Range: 0°C To +60°C
• Display Type: 3 - 1/2 Digit LCD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 1. DMS-20LCD-4/20S (Unipolar Model) DIP-Switch Settings ➂
➂ When looking up DIP-switch settings in the Tables and the desired display
DMS–20LCD–4/20B (Bipolar Reading Model)
The DMS-20LCD-4/20B's zero-offset circuit differs from the unipolar 'S'
model described above in that with the 'B' model, a half-scale 12mA input
is normally set to display "000". Therefore, all of the of the DIP-switch
settings in Table 2 assume a reading of "000" is desired with a 12mA input.
Display readings other than those shown in Table 2 are possible, contact
DATEL for more information.
When confi guring the DMS-20LCD-4/20B for the fi rst time, or when select-
ing a new range, set both R3 and R7 fully clockwise (roughly 22 turns) to
their minimum offset/minimum-span positions, respectively. Then select
the desired readings from Table 2 and confi gure DIP-switches SW1, SW2,
and SW3 accordingly.
The procedure below illustrates how to calibrate the DMS-20LCD-4/20B
to its factory-calibrated readings of "–1000" with a 4mA input and "1000"
with a 20mA input. When performing DIP-switch settings, be sure the DIP-
switch's small actuators are fi rmly engaged in their fully-ON or fully-OFF
positions.
1. Set both R3 and R7 fully clockwise.
2. Select DIP-switch setting #1 from Table 2.
3. Apply a precision 12mA input and adjust R3 until the meter's display
4. Apply a precision 20mA input and adjust R7 until the meter's display
5. Apply a precision 4mA input and the display should read "–1000".
1. Desired display readings are:
Examples (DMS-20LCD-4/20B-Bipolar Model)
Display Reading
1. 000 to 1050-1999
2. 000 to 650-1350
3. 000 to 450-800
4. 000 to 300-500
5. 000 to 200-300
readings can be achieved with either of two different settings, using the higher
setting # will produce less sensitive offset (R3) and span (R7) adjustments.
Please keep in mind that the DMS-20LCD standard meter (from which the DMS-
20LCD-4/20 is derived) has an accuracy specifi cation of ±2 counts (max.). Thus,
it may not always be possible to obtain the exact desired display reading.
4mA
reads "000".
reads "1000".
Repeat steps 3 and 4 to make sure the two adjustments did not
affect one another.
Use DIP-switch setting #5 in Table 2 and enable decimal point DP2 via
SW5. Apply 12mA and adjust R3 so the display reads "0.00". Apply
4mA = "–1.00"
20mA = "1.00"
20mA
SW1
Off
On
Off
Off
On
www.murata-ps.com/dpm
SW2
1
Off
Off
On
Off
On
2
3
ON
SW3
Off
Off
Off
On
On
4
5
6
4-20mA Input Loop-Powered Ultra-Low 1.8V Loop Drop
T
2. Desired display readings are:
3. Desired display readings are:
DMS-20LCD-4/20P (Positive Reading Model)
The DMS-20LCD-4/20P’s Zero-Offset circuit is optimized to produce
positive readings at both 4mA and 20mA input levels. As shown in Table
3’s fi rst three columns, a 4mA input can be typically adjusted (using
R3, Zero/Offset Adjust) to display any positive reading between “000”
and “800”. The corresponding 20mA-input reading is then added to the
4mA offset as a differential whose magnitude is varied by adjusting R7
(Gain/Span Adjust).
The ‘Differential Range’ column in Table 3 lists the nominal differential
display-readings which can be obtained with R7 at, or very close to, its
full-clockwise, minimum span position. The Differential Range column can
be used as a guide when confi guring the meter for the majority of user
applications. Higher differential ranges are obtainable; however, the use
of higher differential readings results in correspondingly-lower positive
readings with 4mA inputs, that is, R3’s clockwise adjustment-range is re-
duced. Example #3 below illustrates this concept. Please contact DATEL
if there is any doubt as to whether or not the DMS-20LCD-4/20P can be
confi gured for your display readings requirements.
able 2. DMS-20LCD-4/20B (Bipolar Model) DIP-Switch Settings ➂
Display Reading
1. –600 to –1000
2. –350 to –650
3. –250 to –400
4. –150 to –250
5. –100 to –150
20mA and adjust R7 so the display reads "1.00". Apply 4mA and
verify that the display reads "–1.00", readjust R3 and R7 if necessary.
Use DIP-switch setting #2 in Table 2. Apply 12mA and adjust R3 so
the display reads "000". Apply 20mA and adjust R7 so the display
reads "450". Apply 4mA and verify that the display reads "–450".
Repeat adjustment procedure if necessary. For these display read
ings, no decimal points are used. Set SW4, SW5 and SW6 to OFF.
Notice that these readings can be obtained using either DIP-switch
setting #1 or DIP-switch setting #2 in Table 2. In situations like this
where DIP-switch settings overlap, less-sensitive R3/R7 adjustments
can be achieved if the higher DIP-setting # is selected (setting #2
in this example). Apply 12mA and adjust R3 so the display reads
"000". Apply 20mA and adjust R7 so the display reads "650". Apply
4mA and verify that the display reads "–650". Repeat adjustment
procedure if necessary.
4mA
DMS-20LCD-4/20 Series
4mA = "–450"
20mA = "450"
4mA = "–650"
20mA = "650"
Technical enquiries email: [e-mail], tel:
12mA
3½ Digit LCD Display Process Monitors
000
000
000
000
000
600 to 1000
350 to 650
250 to 400
150 to 250
100 to 150
20mA
MPM_DMS20LCD-420.B03 Page 3 of 6
SW1
Off
On
Off
Off
On
1
1
2
2
SW2
3
3
ON
ON
Off
Off
On
Off
On
[phone]
4
4
5
5
SW3
Off
Off
Off
On
On
6
6