Texmate, Inc. Tel. (760) 598-9899 • www.texmate.com
Page 6
DX-35_UL DS (DX1_UL)
Input Module Component Glossary
ZERO ADJUST Header
When this header is provided, it works in
conjunction with the ZERO OFFSET RANGE
Header, and expands the ZERO pot’s offset
capability into five equal negative steps or five
equal positive steps. This enables virtually any
degree of input signal offset required to display
any desired engineering unit of measure.
ZERO OFFSET RANGE Header
When provided, this three position header
increases the ZERO pot’s capability to offset the
input signal, to ±25% of the digital display span.
For example a Negative offset enables a 1 to 5V
input to display 0 to full scale. The user can select
negative offset, positive offset, or no offset (ZERO
pot disabled for two step non-interactive span and
offset calibration).
Basic standard range calibration of direct reading
modules that utilize either Auto Zero or a ZERO pot, an
INPUT RANGE Header and or a SPAN pot.
1 If the module has an INPUT RANGE Header, reposition the
jumper clip to select the desired input signal range.
2. Apply a zero input or short the input pins. The display will auto
zero, or if the module has a ZERO pot, it should be adjusted until
the display reads zero.
3 Apply a known input signal that is at least 20% of the full scale
input range and adjust the SPAN pot until the display reads the
exact input value.
4 Decimal Points. The selection or positioning of decimal points
has no effect on the calibration of the modules
Wide range scaling, in engineering units not requiring
offsets, with modules that utilize auto-zero or a ZERO
pot, a SPAN RANGE Header and or a SPAN ADJUST
Header.
Texmate’s unique SPAN ADJUST and SPAN RANGE Headers
provide the circuit equivalent of an ultra-precision one megohm 75
or 150 turn potentiometer that can infinitely scale down any Input
Signal SPAN to provide any full scale Digital Display Span from
Input Module Calibration
LO RANGE
HI RANGE
10%
SPAN Pot %
10%
10%
10%
10%
10%
Signal Span %
20%
30%
40%
50%
1
SPAN Adjust
Header position
Span Adjust Header
Span Adjust Header
Span Range Header
2
3
4
5
10%
10%
10% 10%
10%
60%
70%
80% 90%
100%
1
2
3
4
5
< Decrease Span Increase >
1 2
3
4 5
< Decrease Span Increase >
1 2
3
4 5
Equivalent
Circuit
Acts like a
150 Turn
Potentiometer
Low Range
High Range
Input LO
Input HI
HI
LO
< Increase Zero Decrease >
5 4
3
2 1
< I
ncre
ase
Zer
o D
ecre
ase
>
5
4
3
2
1
Input and Output Pins
On most modules Pin 1 is the Signal High input
and Pin 3 is the Signal Low input. Typically Pin 2
is used for Excitation Voltage output.
HI
LO
24V
Exc
Offset
0
–
+
0
–
+
INPUT RANGE Header
Range values are marked on the PCB. Typically
two to four positions are provided, which are
selected with either a single or multiple jumper
clip. When provided, a custom range position is
only functional when the option has been factory
installed.
Custom
200V
20V
2V
24V DC Output Header
On some modules this header enables a 24V
DC 25mA (max) Excitation/Auxiliary output to be
connected to Pin 2.
ON
OF
F
OFF
ON
24V EXC
< Increase Span Decrease >
5 4
3
2 1
< I
ncre
ase
Spa
n D
ecre
ase
>
5 4
3
2 1
SPAN RANGE Header
When this header is provided it works in
conjunction with the SPAN ADJUST Header by
splitting its adjustment range into a Hi and a
Lo range. This has the effect of dividing the
adjustment range of the SPAN pot into ten equal
10% steps across 100% of the input Signal Span.
Range
HI
LO
HI
LO
Zero Offset Range Header
0 +
–
–20%
ZERO Pot %
–20% –20% –20% –20%
No
Offset
NEGATIVE OFFSET
POSITIVE OFFSET
–1200 or more counts
Offset Range
+20% +20% +20% +20% +20%
+1200 or more counts
5
ZERO Adjust
Header position
4
3
2
1
1
2
3
4
5
75 Turn Potentiometer
–
0
Equivalent
Circuit
< Increase Zero Decrease >
5 4
3
2 1
< Decrease Zero Increase >
1 2
3
4 5
75 Turn Potentiometer
+
0
Zero Pot
Disabled
SPAN
Turn Clockwise to
Increase Reading
To the
Right Rear
SPAN Potentiometer (Pot)
If provided, the 15 turn SPAN pot is always on the
right side (as viewed from the rear of the meter).
Typical adjustment is 20% of the input signal
range.
20%
SPAN Pot %
20%
20%
20%
20%
20%
Signal Span %
40%
60%
80%
100%
1
SPAN Adjust
Header position
2
3
4
5
< Decrease Span Increase >
1 2
3
4 5
Acts like 75 Turn 1 Mega ohm Potentiometer
Input LO
Input
HI
Equivalent
Circuit
SPAN ADJUST Header
This unique five-position header expands the
adjustment range of the SPAN pot into five equal
20% steps, across 100% of the input Signal Span.
Any input Signal Span can then be precisely scaled
down to provide any required Digital Display span
from 1999 counts to 001 (one count).
ZERO
Turn Clockwise to
Increase Reading
To the
Left Rear
15 Turn Potentiometer
⊕
+
100 Counts
⊕
–
100 Counts
–
0
+
ZERO Potentiometer (Pot)
If provided, the ZERO pot is always to the left
of the SPAN pot (as viewed from the rear of the
meter). Typically it enables the input signal to be
offset ±5% of full scale (-100 to +100 counts).
Zero Offset Range Header
0 +
–
No
Offset
NEGATIVE OFFSET
Decreases Digital Reading
POSITIVE OFFSET
Increases Digital Reading
15 Turn Potentiometer
–
0
Equivalent
Circuit
15 Turn Potentiometer
+
0
Zero Pot
Disabled
⊕
–
500 Counts
Offset Range
– 100% of Offset
ZERO Pot%
⊕
+
500 Counts
+ 100% of Offset
WARNING
:
AC and DC input signals and power supply
voltages can be hazardous. Do Not insert, remove or handle
modules with live wires connected to any terminal plugs.
!
