www.murata-ps.com/support
DMS-20PC-4/20 Series
Subminiature 4-20mA Loop-Powered
3½ Digit LED Process Monitors
MPM_DMS20PC-4/20.D01
Page 2 of 6
OPERATING AND SETUP INSTRUCTIONS
Performance/Functional Specifi cations
Typical at T
A
= +25°C, unless otherwise noted.
➀
The DMS-20PC-4/20, using any of the DIP-switch settings described above, can
withstand overcurrents, including those resulting from accidental reverse-polarity
connections, up to ±40mA without sustaining any damage.
➁
Because Murata Power Solutions' DMS-4/20 loop-powered meters employ active
circuitry to convert the loop current into a voltage, the meters' effective series
impedance varies in a manner that maintains the loop voltage drop constant
over the full 4-to-20mA current range. Listed impedance specifi cation applies at
20mA.
➂
When looking up DIP-switch settings in the Tables and the desired display
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-20PC standard meter (from which the DMS-
20PC-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.
1
. Set R7 (full scale span/gain adjust) and R3 (zero/offset adjust) fully
clockwise, roughly 22 turns, and place SW1-SW6 to OFF.
2
. Select DIP switch setting #2.
3
. Apply a precision 4mA input, with proper polarity, and adjust R3 until
the meter's display reads "000".
4.
Apply a precision 20mA input and adjust R7 until the meter's display
reads "1000". Repeat steps 3 and 4 to make sure the adjustments do
not affect one another.
5
. Select the appropriate decimal point by setting SW4, SW5 or SW6 to
ON (DP1, DP2 or DP3 respectively).
NOTE: If a display reading other than "000" to "1000" is desired,
refer to DIP–Switch Settings Table 1 for SW1–SW3 settings.
Display
Reading
SW1 SW2 SW3
4mA
20mA
1.
000 to 1050-1999
Off
Off
Off
2.
000 to 650-1350
On
Off
Off
3.
000 to 450-800
Off
On
Off
4.
000 to 300-500
Off
Off
On
5.
000 to 200-300
On
On
On
Table 1. DMS-20PC-4/20S (Unipolar Model) DIP-Switch Settings
DMS-20PC-4/20S-C
Unipolar reading, loop-powered LED meter
DMS-20PC-4/20B-C
Bipolar reading, loop-powered LED meter
DMS-20PC-4/20P-C
Positive reading, loop-powered LED meter
DMS-BZL3-C
Bezel
assembly
DMS-BZL4-C
Bezel assembly with sealing gasket
DMS-20-CP
Panel cutout punch
A panel-mount retaining clip is supplied with each model.
1.
Desired display readings are:
4mA
="0.00"
20mA = "6.00"
Use DIP-switch setting #3 in Table 1 and enable decimal point DP2 via
SW5. Apply 4mA and adjust R3 so the display reads "0.00". Apply
20mA and adjust R7 so the display reads "6.00".
2.
Desired display readings are:
4mA = "000"
20mA = "800"
Use DIP-switch setting #2 in Table 1. Apply 4mA and adjust R3 so the
display reads "000". Apply 20mA and adjust R7 so the display reads
"800". For these display readings, no decimal points are used. Set
SW4, SW5 and SW6 to OFF.
Examples (DMS-20PC-4/20S-Unipolar Model)
DMS-20PC-4/20S (Unipolar Reading Model)
As shipped, the DMS-20PC-4/20S is factory calibrated to read "000"
for a 4mA input and "1000" for a 20mA input. The following worst-case
procedure assumes the DMS-20PC-4/20S is completely mis-adjusted,
i.e., both potentiometers and the DIP switches are randomly set. 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.
Current Loop Input
Min.
Typ.
Max.
Units
Full Scale Input Range:
➀
+4
–
+20
mA
Input Impedance:
➁
–
250
Ω
Voltage Drop
➁
–
4.5
5.0
Volts
Overcurrent Protection
➀
–
–
±40
mA
Performance
Sampling Rate
2.5 reading per second
Accuracy (1 minute warm-up):
±0.05%FS ±1 Count
Temperature Drift
(0 to +60°C)
–
±0.15
±0.3
Cnts/°C
Display
Display Type and Size
3½ digit, 0.37"/9.4mm high red LED
Polarity Indication
"–" for negative reading
Overrange Indication
"–1____" for negative Vin
"1____" for positive Vin
Physical/Environmental
Operating Temperature
0
–
+60
°C
Storage Temperature
–40
–
+75
°C
Humidity (non-condensing)
0
–
95
%
Case Material
Polycarbonate
Weight
0.6 ounces (17 grams)
Ordering Information
1
2
3
4
5
6
ON
1
2
3
4
5
6
ON
