DMS-20PC-4 MURATA-PS [Murata Power Solutions Inc.], DMS-20PC-4 Datasheet - Page 4

• Manufacturer Part Number: DMS-20PC-4
• Manufacturer: MURATA-PS [Murata Power Solutions Inc.]

fully clockwise (roughly 22 turns) to their minimum offset/minimum span
positions, respectively.
The next step is to calculate the required display differential-reading; this
is accomplished by subtracting the desired 4mA display reading from
the desired 20mA display reading, disregarding decimal points. Then,
using the calculated differential display-reading to select the appropriate
DIP-switch setting # from Table 3, configure DIP-switches SW1, SW2, and
SW3 accordingly. Make certain that the DIP-switch’s small actuators are
firmly engaged in their fully-ON or fully-OFF positions.
The procedure below describes how to calibrate the meter for an applica-
tion which the DMS-20PC-4/20P easily accommodates: displaying the
output of a 4-20mA transmitter, that is, “04.0” with a 4mA input and “20.0”
with a 20mA input.
1. Set R3 fully counterclockwise (minimum offset position) and R7 fully
2. Subtract 040 from 200 to yield a differential value of 160; use this value
3. Set the transmitter’s output to 4.0mA and carefully adjust R3 clockwise
4. Set the transmitter’s output to 20.0mA and adjust R7 counterclock-
5. Set the transmitter back to 4.0mA and slowly adjust R3 clockwise until
Table 3. DMS-20PC-4/20P (Positive Reading Model)
DIP-Switch Settings
Display Reading
Differential Range
clockwise (minimum differential span position), roughly 22 turns.
to select DIP-switch setting #5 in Table 3. Enable decimal point DP3 by
placing SW6 to the ON position.
until the meter’s display reads “000”.
wise until the meter’s display reads “16.0”.
the display reads “04.0”. Reapply 20.0mA and the display should now
read “20.0”. Repeat steps 3, 4 and 5 to make sure the adjustments did
not affect one another.
1. 800-1400
2. 500-800
3. 350-500
4. 250-350
5. 150-250
4mA Input
900
850
800
750
750
20mA Input
1700
1350
1150
1000
900
SW1 SW2
www.murata-ps.com
Off
On
Off
Off
On
Off
Off
On
Off
On
SW3
Off
Off
Off
On
On
Table 4. Decimal Point Settings
Examples (DMS-20PC-4/20P-Positive Model)
1. Desired display readings are:
2. Desired display readings are:
Use DIP-switch setting #4 in Table 3 since subtracting 650 from 950
yields a differential value of 300. Apply 4mA and adjust R3 until the
display reads “000”. Apply 20mA and adjust R7 until the display reads
“300” (the differential value previously calculated). Apply 4mA and
adjust R3 until the display reads “650”. Apply 20mA and verify that the
display reads “950”.
This example illustrates the DMS-20PC-4/20P’s capability to display
higher differential readings than those indicated in Table 3. This
example also illustrates how the DMS-20PC-4/20P can be used to
display the output levels of a 4-20mA loop transmitter with higher preci-
sion (0.01mA versus 0.1mA) than described above.
Subtracting 400 from 1999 yields a differential of 1599, a value not
listed in Table 3. However, use DIP-switch setting #1 in Table 3 since
this setting has the highest overall offset/span adjustment capabilities.
Enable DP2 via SW5 then apply 4mA and adjust R3 so the display
reads “0.00”. Apply 20mA and adjust R7 so the display reads “15.99”.
Apply 4mA and adjust R3 until the display reads “4.00”. Apply 20mA
and check to see that the display reads “19.99” or just overranges
(“1—“). Repeat adjustment procedure if necessary.
4mA = “650”
20mA = “950”
4mA = “4.00”
20mA = “19.99”
SW4
DP1
DMS-20PC-4/20 Series
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Subminiature 4-20mA Loop-Powered
3½ Digit LED Process Monitors
SW5
DP2
MPM_DMS20pc-420.C02 Page 4 of 6
1
1
SW6
2
DP3
2
3
3
ON
ON
4
4
[phone]
5
5
6
6