Instructions
APD 2057
Calibration
Front-mounted Zero and Span potentiometers for each channel can
be used to compensate for load and lead variations.
1. Apply power to the module and allow min. 30 minute warm up time.
2. Using an accurate voltmeter on terminals 18 and 20 adjust the
excitation voltage fine adjustment potentiometer to the strain
gauge manufacturer's recommended value.
3. Using an accurate calibration source, provide an input to the
module equal to the minimum input required for the application.
4. Using an accurate measurement device for the output, adjust
the Zero potentiometer for the exact minimum output desired.
The Zero control should only be adjusted when the input signal
is at its minimum. This will produce the corresponding minimum
output signal. For example: 4 mA for a 4-20 mA output or –10 V
for a ±10 V output.
5. Set the input at maximum, and then adjust the Span pot for the
exact maximum output desired. The Span control should only
be adjusted when the input signal is at its maximum. This will
produce the corresponding maximum output signal. Example:
for 4-20 mA output, set the Span control to 20 mA.
6. Repeat adjustments for both channels for maximum accuracy.
Ch. 2 Sensitivity Adjustment
This multi-turn potentiometer provides an adjustable threshold
level that the incoming signal must overcome before an output
can be produced. This is used to limit noise and minimize false
input signals that may cause erroneous readings.
Fully clockwise: (max. sensitivity), input threshold is ±25 mV.
Fully counterclockwise: (min. sensitivity), input threshold is ±2.5 volts.
Output Test Function
When the Test button is depressed it will drive the output with a
known good signal that can be used as a diagnostic aid during
initial start-up or troubleshooting. When released, the output will
return to normal.
Each Test Cal. potentiometer is factory set to approximately 50%
output. Each can be adjusted to set the test output from 0 to 100%
of the output span. Press and hold the Test button and adjust the
corresponding Test Cal. potentiometer for the desired output level.
They may optionally be externally wired for remote test operation or
a manual override. See wiring diagram at right.
Operation
The APD 2057 accepts one strain gauge input and one frequency
input and provides two optically isolated DC voltage or current
outputs that are linearly related to the inputs.
Green LoopTracker
®
input LEDs provide a visual indication that
each signal is being sensed by the input circuitry of the module.
They also indicates the input signal strength by changing in inten-
sity as the process changes from minimum to maximum.
If an LED fails to illuminate, or fails to change in intensity as the
process changes, check the module power or signal input wiring.
Two red LoopTracker output LEDs provide a visual indication that the
output signals are functioning. They become brighter as the input
and each corresponding output change from minimum to maximum.
For a current output the red LED will only light if the output loop
current path is complete. For either current or voltage outputs,
failure to illuminate or a failure to change in intensity as the pro-
cess changes may indicate a problem with the module power or
signal output wiring. Note that it may be difficult to see the LEDs
under bright lighting conditions.
APD 2057
Channel 1
Channel 2
Strain Gauge to DC
Frequency to DC
Isolated Transmitter
Isolated Transmitter
Test Cal.
Span
Zero
Test
Output
Loop
Tracker
Test Cal.
Span
Zero
Test
Output
Input
Loop
Tracker
Loop
Tracker
Input
Loop
Tracker
Channel 1
Channel 2
®
Excitation
Sensitivity
14
13
15 16
10
9
11 12
External
Contacts
for Test
Function
–
+ 20V
–
+ 20V
mA
Device 2
R
i
mA
Device 1
R
i
6
5
7
8
2
1
3
4
Ch. 1
Ch. 2
Voltage
Output
–
+
Voltage
Device 1
–
+
Voltage
Device 2
2
1
3
4
Ch. 1
Ch. 2
6
5
7
8
–
+
mA
Device 2
R
i
Loop
Power
Source 2
–
+
+
–
mA
Device 1
R
i
Loop
Power
Source 1
Ch. 1
Ch. 2
2
1
3
4
6
5
7
8
+
–
See manufacturer's
specifications for
wiring designations.
Shield wires should
be grounded at one
end only.
18
17
19 20
Excitation
+
Strain
gauge
Signal
–
Excitation
–
Precautions
WARNING! All wiring must be performed by a qualified electrician
or instrumentation engineer. See diagram for terminal designa-
tions and wiring examples. Consult factory for assistance.
WARNING! Avoid shock hazards! Turn signal input, output, and
power off before connecting or disconnecting wiring, or removing
or installing module.
Précautions
ATTENTION! Tout le câblage doit être effectué par un électricien
ou ingénieur en instrumentation qualifié. Voir le diagramme pour
désignations des bornes et des exemples de câblage. Consulter
l'usine pour assistance.
ATTENTION! Éviter les risques de choc! Fermez le signal d'entrée,
le signal de sortie et l'alimentation électrique avant de connecter
ou de déconnecter le câblage, ou de retirer ou d'installer le module.
Electrical Connections
Polarity must be observed for signal wiring connections. If the
input and/or output do not function, check wiring and polarity.
Each product is factory configured to your exact input and output
ranges as indicated on the serial number label.
Outputs
For milliamp ranges determine if your devices provide power to
the current loop or if the loop must be powered by the APD mod-
ule. Typical voltage may be 9-24 VDC at your device's terminals if
it provides power to the loop.
28 Power AC or DC –
26 Earth Ground
25 Power AC or DC +
26
25
27
28
To maintain full isola-
tion avoid combining
power supplies in
common with inputs,
outputs, or unit power.
2 Wire
22
21
23
24
–
+15 VDC
+Sig
2 wire using 15 V supply
See sensor specs. if
bleed resistor is required
15 k
Ω
typ.
2 Wire
22
21
23
24
2 wire self-generating
–
+Sig
3 wire NPN
See sensor specs. if load
resistor is required
NPN
22
21
23
24
–
+15 VDC
+Sig
Load resis.
3 wire PNP
See sensor specs. if
load resistor is required
22
21
23
24
–
+15 VDC
+Sig
PNP
Load resis.
Bridge Input Channel 1
– Te Terminal
Strain gauge signal input
17
(
+)
19 (
–)
Excitation voltage
18 (
–)
20
(
+)
Input 1, Bridge, Strain Gauge, Load Cell
Refer to wiring diagram at right and strain gauge manufacturer’s
data sheet for wiring and color-coding. Polarity must be observed
when connecting input. Sensor shield wire (if equipped) should be
grounded at one end only.
The excitation voltage is factory set and should match the sen-
sor manufacturer's recommendations. A front potentiometer
allows approximately ±10% fine adjustment of the excitation
voltage.
CAUTION: Never short the excitation leads together. This
will cause internal damage to the module.
Input 2, Frequency
The input range is pre-configured at the factory. No input calibra-
tion is necessary. The frequency input is compatible with most
types of sensors that product a minimum 100 mV amplitude
change and a minimum 5 microsecond pulse width.
A 15 VDC supply is available to power the sensor if required.
Always refer to the sensor manufacturer's data sheet to deter-
mine supply voltage compatibility and proper wiring.
Frequency Sensor Ch. 2
Signal
Com.
Sensor
Power
Signal
Input
2 wire or Namur
requiring external power
n/a
22
(
+15 V)
23
(
+)
2 wire self generating (VR)
21 (
–)
n/a
23
(
+)
3 wire PNP or NPN
21 (
–) 22
(
+15 V)
23
(
+)
Mounting to a DIN Rail
Install module vertically on a 35 mm DIN rail in a protective enclo-
sure away from heat sources. Do not block air flow. Allow 1" (25
mm) above and below housing vents for air circulation.
1. Tilt front of module down and position
the lower spring clips against the bottom
edge of DIN rail.
2. Push front of module upward until upper
mount snaps into place.
Removal
Avoid shock hazards! Turn signal input,
output, and power off.
1. Push up on bottom back of module.
2. Tilt front of module downward to
release upper mount from top edge of
DIN rail.
3. The module can now be removed from
the DIN rail.
Spring Clips
Upper Mount
Module Power Terminals
Check label for module operating voltage to make sure it matches
available power. The power supplies are fuse protected and the
unit may be returned to API for fuse replacement.
When using DC power, either polarity is acceptable, but for consis-
tency, wire positive (+) to terminal 25 and negative (–) to terminal 28.
Device for Output Channel 1
Terminal Terminal
Voltage input device.
3 (
–)
4
(
+)
Unpowered or passive mA input device.
APD module provides the loop power.
3 (
–)
4
(+20 V)
mA input device powers the current loop.
2 (
–)
3
(
+)
Device for Output Channel 2
Terminal Terminal
Voltage input device.
7 (
–)
8
(
+)
Unpowered or passive mA input device.
APD module provides the loop power.
7 (
–)
8
(+20 V)
mA input device powers the current loop.
6 (
–)
7
(
+)
Sensor Load
The frequency signal input is capacitively coupled to prevent any
DC in the input. Some sensors, typically those without an internal
load resistor, require a resistive load in order to function.
The resistor value may be specified by the sensor manufacturer
as the "minimum resistive load" or calculated from the sensor
manufacturer's specified "load current range".
The 15 VDC power supply is capable of providing 25 mA. A load current
range of 3 mA to 25 mA would typically use a 5 k
Ω
to 500
Ω
resistor.
Cu 60/75°C
conductors
14 AWG
max.
To avoid
damage to
the module,
do not
make any
connections
to unused
terminals
Wire terminal
torque
0.5 to 0.6 Nm or
4.4 to 5.3 in-lbs
API maintains a constant effort to upgrade and improve its products.
Specifications are subject to change without notice. See api-usa.com for
latest product information. Consult factory for your specific requirements.
WARNING:
This product can expose you to chemicals includ-
ing nickel, which are known to the State of California to cause
cancer or birth defects or other reproductive harm. For more
information go to www.P65Warnings.ca.gov
Current
Sourcing
Output
Current
Sinking
Output
Module
powers mA
output loop
Module mA
output is
unpowered
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