DayTronic 3700 Series User manual

MODEL
3778P
AC STRAIN GAGE CONDITIONER
SB.1.1
INSTRUCTION MANUAL
3700
Instrument Series

WARNING
Death, serious injury, orfire hazard could result from improper connection of this instrument. Read and understand this
manual before connecting this instrument. Follow allinstallation andoperating instructions while using this instrument.
Connection of this instrument must be performed in compliance with the National Electrical Code (ANSI/NFPA 70-2014) of
USA and any additional safety requirements applicable toyour installation.
Installation, operation, and maintenance ofthis instrument must be performed by qualified personnel only. The National
Electrical Code defines a qualified person as “one who hasdemonstrated the skills and knowledge related to theconstruction
and operation of the electrical equipment and installations, and who hasreceived safety training on the hazards involved.”
Qualified personnel who work on or near exposed energized electrical conductors must follow applicable safety related
work practices and procedures including appropriate personal protective equipment incompliance with the Standard for
Electrical Safety Requirements forEmployee Workplaces (ANSI/NFPA 70E-2012)of USA andanyadditional workplace safety
requirements applicable toyour installation.
ADVERTENCIA
Una conexión incorrecta de este instrumento puede producir lamuerte, lesiones graves y riesgo de incendio. Lea y entienda
este manual antes de conectar. Observe todas las instrucciones de instalación y operación durante elusode este
instrumento.
La conexión deeste instrumento a unsistema eléctrico se debe realizar enconformidad conelCódigo Eléctrico Nacional
(ANSI/NFPA 70-2014)de los E.E.U.U., además de cualquier otra norma de seguridad correspondiente a su
establecimiento.
La instalación, operación y mantenimiento de este instrumento debe ser realizada por personal calificado solamente. El
Código Eléctrico Nacional define a una persona calificada como "una que esté familiarizada con la construcción y operación del
equipo y con los riesgos involucrados."
El personal cualificado que trabaja encendido o acerca a los conductores eléctricos energizados expuestos debe seguir
prácticas y procedimientos relacionados seguridad aplicable deltrabajo incluyendo elequipo protector personal apropiado
en conformidad con elestándar para los requisitos deseguridad eléctricos para los lugares de trabajo del empleado (ANSI/
NFPA 70E-2012)de los E.E.U.U. y cualquier requisito de seguridad adicional dellugar de trabajo aplicable a suinstalación.
AVERTISSEMENT
Si l'instrument est mal connecté, lamort, desblessures graves, ou un danger d'incendie peuvent s'en suivre. Lisez
attentivement cemanuel avant de connecterl'instrument. Lorsque vous utilisez l'instrument, suivez toutes les
instructions d'installation etdeservice.
Cet instrument doit être connecté conformément auNational Electrical Code (ANSI/NFPA 70-2014)des Etats-Unis et à
toutes les exigences desécurité applicables à votre installation.
Cet instrument doit être installé, utilisé et entretenu uniquement par un personnel qualifié. Selon le National Electrical
Code, une personne est qualifiée si "elle connaît bien la construction et l'utilisation de l'équipement, ainsi que les dangers
que cela implique".
Le personnel qualifié qui travaillent dessus ou s'approchent desconducteurs électriques activés exposés doit suivre des
pratiques en matière et des procédures reliées par sûreté applicable de travail comprenant le matériel de protection
personnel approprié conformément à lanorme pour desconditions de sûreté électriques pour les lieux de travail des
employés (ANSI/NFPA 70E-2012)des Etats-Unis ettoutes les conditions de sûreté additionnelles de lieu de travail
applicables à votre installation.
Page 1

WARNUNG
Der falsche Anschluß dieses Gerätes kann Tod, schwere Verletzungen oder Feuer verursachen. Bevor Sie dieses Instrument
anschließen, müssen Sie dieAnleitung lesen und verstanden haben. Bei derVerwendung dieses Instruments müssen alle
Installation- und Betriebsanweisungen beachtet werden.
Der Anschluß dieses Instruments muß in Übereinstimmung mit den nationalen Bestimmungen für Elektrizität (ANSI/NFPA
70- 2014)der Vereinigten Staaten, sowie allen weiteren, inIhrem Fall anwendbaren Sicherheitsbestimmungen, vorgenommen
werden.
Installation, Betrieb und Wartung dieses Instruments dürfen nur von Fachpersonal durchgeführt werden. In dem nationalen
Bestimmungen fürElektrizität wird einFachmann als eine Person bezeichnet, welche "mit der Bauweise und dem Betrieb des
Gerätes sowie den dazugehörigen Gefahren vertraut ist."
Qualifiziertes Personal, das anbearbeiten oder herausgestellte angezogene elektrische Leiter sich nähern, mußanwendbare
Sicherheit bezogener Arbeit Praxis und Verfahren einschließlich passende persönliche schützende Ausrüstung gemäß dem
Standard für elektrische Sicherheitsauflagen für Angestellt-Arbeitsplätze (ANSI/NFPA 70E-2012)derVereinigten Staaten
und alle zusätzlichen Arbeitsplatzsicherheitsauflagen folgen, dieauf Ihre Installation anwendbar sind.
Safety Precautions
The following safety precautions must be followed whenever any type of voltage or current connection is being made to the
instrument.
oBefore connecting to electric circuits or pulse initiating equipment, open their related breakers or disconnects. It is
recommended NOT TO install any connection of the instrument on live power lines. Only Qualified Service personnel that
have demonstrated the abilities and received the proper safety training are capable of connecting to live circuits.
oConnections must be made to the instrument first, then connect to the circuit to be monitored.
oWear proper personal protective equipment, including safety glasses and insulated gloves when making connections to
power circuits.
oHands, shoes and floor must be dry when making any connection to a power line.
oBefore each use, inspect all cables for breaks or cracks in the insulation. Replace immediately if defective.
oIf the equipment is used in a manner not specified in this user’s guide, the protection provided by the equipment may be
impaired.
Page 2

Medidas de seguridad
Las medidas de seguridad siguientes deberán observarse cuando serealice cualquier tipo de conexión al instrumento.
οCuando se haga conexiones a circuitos eléctricos o a equipo de activación por pulso, deberá abrirse sus respectivas cajas
de seguridad. NO deberá hacerse ninguna conexión del instrumento en líneas eléctricas bajo tensión.
οLas conexiones deberán hacerse primero al instrumento y, luego, al circuito a ser monitorizado.
οAl hacer conexiones a circuitos eléctricos, deberá utilizar anteojos y guantes protectores.
οSus manos, zapatos y elpiso deberán estar secos entodo momento en que sehaga una conexión a un cable eléctrico.
οVerifique que launidad esté DESACTIVADA antes de conectar sondas en el panel posterior.
οPrevio a cada uso, deberá verificarse que los cables no estén rotos y que elmaterial aislante no tenga rajaduras.
Reemplace de inmediato cualquier parte defectuosa.
Mesures de Sécurité
Les mesures de sécurité suivantes doivent être prises chaque fois qu’un type de connexion quelconque est effectué
sur l’instrument.
οOuvrir les disjoncteurs correspondants lors d’une connexion à descircuits électriques ou à deséquipement de génération
d’impulsions. NE PAS effectuer de connexion d’instrument sur deslignes électriques sous tension.
οUne fois toutes les connexions de l’instrument effectuées, connecter aucircuit à contrôler.
οPorter deslunettes de protection et desgants isolants pour effectuer desconnexions aux circuits électriques.
οS’assurerque les mains, les chaussures et le sol soient secs lors de connexions à une ligne électrique.
οS’assurer que l’unité est ÉTEINTE avant de connecter les sondes au panneau arrière.
οInspecter tous les câbles, avant chaque utilisation, pour s’assurer que les isolants ne sont pascoupés ou fendus.
Remplacer immédiatement tous les équipements défectueux.
Page 3

Sicherheitsvorkehrungen
Die folgenden Sicherheitsvorkehrungen sind immer dann zu befolgen, wenn eine Verbindung zum Instrument hergestellt wird.
οÖffnen Sie beim Anschluß an elektrische Stromkreise oder Impulsauslösungseinrichtungen die entsprechenden
Unterbrecher. Es dürfen KEINE Anschlüsse an das Instrument unter stromführenden Spannungsleitungen montiert
werden.
οDie Verbindungen müssen zuerst am Instrument und danach an der zu überwachenden Schaltung hergestellt werden.
οTragen Sie Schutzbrillen und Isolierhandschuhe, wenn Sie Anschlüsse an den Stromkreisen vornehmen.
οHände, Schuhe und Fußboden müssen trocken sein, wenn Sie Anschlüsse an den Stromkreisen durchführen.
οStellen Sie sicher, daß das Gerät AUSgeschaltet ist, bevor Sie an der rückwärtigen Konsole Meßfühler anschließen.
οPrüfen Sie vor jedem Gebrauch alle Kabel auf Bruchstellen und Risse in der Isolierung. Wechseln Sie schadhafte Kabel
sofort aus.
Standard Accessories
Standard
accessories The following table lists the 3700 standard accessories.
Description Part Number
*US Power Cord USSTDCORD (900744)
*European Power Cord EUROSTDCORD (115369-G1)
*United Kingdom Power Cord UKSTDCORD (115368-G2)
*Australian Power Cord AUSTDCORD (901347)
3778 Manual 92364.00
*User specified, one standard only.
3778 Quick Reference Guide 92369.00
5 Pin connector, analog signals
8 Pin connector, transducer
10 Pin connector, logic
25657-LF
25658-LF
25606.00
Desk top feet (4ea.) 35058.00
Page 4

M ODEL 3778 AC STRAIN GAGE PANEL METER
3778
1.A.0.3778
1
G ENERAL D ESCRIPTION AND S PECIFICATIONS
The Model 3778 is a single-channel panel instrument of phase-sensitive carrier-amplifier
design, intended for applications involving transformer coupled rotary torque sensors or
traditional wheat-stone bridge sensors requiring noise rejection due to specific carrier frequency
excitation – signal design. The 3778 will supply excitation, condition and provide a calibrated
Engineering Unit's display and analog output signal for the measurement of force, load, torque
and other parameters associated with AC based strain gage sensors. The 3778 is designed for use
with standard full bridge sensors with user selectable gain, zero, manual phase control and
selectable analog output of voltage and current. Display is user configured for engineering unit
scaling up to +/- 199950.
The Model 3778 is calibrated either by the “two-point (dead-weight)” process involving known
zero & span standards or via the shunt calibration method using front panel (or rear connection)
"±CAL" push button controls. Also provided is a "TARE" button for quick zero offset alignment.
FRONT PANEL VIEW OF 3778 CONTROLS (Front Display Cover Removed)
1 2 3 4 5 6 7
CF
CCFF
1 . X . X . X . X 0
FINE ADJUST
ZERO SPAN 1.X.X.X.X 0
ZERO SPAN
WIDE ADJUST
5000
10000
20000
SYM
DISPLAY SPAN
TARE+ CAL - CAL
1 2 3 4 5 6 7
ANALOG CTRL
FINE ADJUST
COARSE ZERO
FINE ZERO
COARSE SPAN
FINE SPAN
WIDE ADJUST
ZERO
SPAN
DISPLAY CONFIGURATION
Sw 1,2,3,4 DECIMAL POINT PLACEMENT
Sw 5 DUMMY ZERO
Sw 6 & 7 DISPLAY RESOLUTION
+ CAL + SHUNT
- CAL - SHUNT
TARE
ANALOG CONTROL SETTINGS
1 – VOLTAGE OUTPUT – 5.0 or 10.0 VDC
2 – CURRENT OUTPUT – 4-20 Ma
3 – ANALOG FILTER
4 – ANALOG FILTER
5 – SHUNT INTERNAL / EXTERNAL
6 – EXCITATION FREQUENCY
7 – Not Used
DISPLAY SPAN
COARSE
FINE
SYMMETRY
MANUAL PHASE
OFF
Shunt
Reference
Jumper
Page 5

M ODEL 3778 AC STRAIN GAGE PANEL METER
3778 SPECIFICATIONS
Measurement Range: Adjustable 0.5 mV/V to 5.0 mV/V; nominal full-scale
Transducer Types: Conventional 4-arm strain gage bridges, typically transformer coupled - 120 to 10k Ohm
Excitation:3.28or 5.0 KHz (selectable);Nominal 2.77 V RMS up to 70 mA, sensed
Power Supply: Voltage 90 - 250 VAC, 47 -63 Hz
Consumption 10 Watts
Physical Parameters: 5. 68” W x 2. 84” H x 7. 06” D; weight - 3. 25 Lbs.
Analog Output: selectable; ± 5, ±1 0 VDC, 4 -20 mA or 4 -12 -20 mA (20 % over -range on voltage outputs only)
Operating Temperature: 0 to +55 Degrees C, 5 to 95% relative humidity, non-condensing
Altitude: 2000m (6560 ft) maximum
Installation Category: Installation Category II, Pollution Degree 2
Amplifier:
Normal - ModeRange: ± 0.2V rms operating; ± 8 Vwithout instrument damage
Common-Mode Range: ± 3V
Input Impedance: Differential >10 MΩ
Offset: vs. Temperature: ±30 ppm µV/°C; vs. Time: ±10 ppm/month
Gain Accur acy: Limited only bycalib ration accu racy
Gain Stability: vs. Temperature: ±30ppm/°C; vs. Time: ±10ppm/month
Linearity:better than ± 0.03% of full scale
Filter:3-pole modified Butterworth; 3 dB down at 2 Hz, 20 Hz or 200 Hz; selectable
Fast output always enabled, 1 KHz response (J3 Pin 3).
Step-Response Settling Times for the 3778 (in milliseconds)
3db Frequency To within 1% within .1% within .02%
Fast Output 1000 Hz 0.7 0.9 1.0
Selectable Output 200 Hz 3.7 5.0 5.6
20 Hz 37 50 56
2 Hz 370 500 560
1.a P ANEL M OUNTING
You can easily mount the instrument in your own precut panel. Cutout dimensions for a
panel-mounted unit are standard
DIN ; panel thickness should not exceed 6 mm (0.24
in).Simply unscrew the two rear-panel CLAMP SCREWS and slide the CLAMP
SLIDES rearwards out of their grooves (THE FRONT BEZEL NEED NOT BE
REMOVED). Insert the unit through the panel cutout, from the front of the panel (if the
unit has rubber feet, these will have to be removed). Then reinstall the CLAMP
SLIDES, and tighten the CLAMP SCREWS until the instrument is securely mounted.
Page 6

M ODEL 3778 AC STRAIN GAGE PANEL METER
The Model 3778 I/O CONNECTIONS are via removable screw terminals which will accept
wire sizes from AWG 12 to 26. NOTE:The recommended transducer cabling would
be eight wire, individually shielded, twisted pair - wired as indicated (Fig. 6) Sense lines
must be connected at the transducer (as recommended) or at the 3778 screw terminals -
as a minimum. Table 1 denotes screw terminal assignments
Rear Panel Connection
HOLD
TARE
LOGIC COM
TARE ENABLE
EXCITATION EXCITATION
SENSE
SENSE
SIGNAL
SIGNAL
CAL SENSE
SHIELD
VDC COM
V OUT SEL
V OUT FAST
4-20 mA COM
4-20 mA OUT
+
_ _
_
+ +
SYNC
M / S ENABLE
R CAL +
SHUNT
SHUNT
R CAL -
Table 1
Connector Screw Terminal
Number Terminal Label Function
J1 1 SYNC Sync Clock connection
J1 2 M/S ENABLE Master/Slave Sync Output Enable
J1 3 HOLD Input - Analog Hold command
J1 4 TARE Input - Analog TARE command
J1 5 TARE ENABLE External TARE Enable
J1 6 LOGIC COM Logic Common
J1 7 R CAL + Remote Positive Shunt Cal command
J1 8 R CAL - Remote Negative Shunt Cal command
J1 9 SHUNT External Shunt Resistor connection
J1 10 SHUNT External Shunt Resistor connection
J2 1 + EXCITATION
J2 2 - EXCITATION
J2 3 + SENSE
J2 4 - SENSE
J2 5 + SIGNAL
J2 6 - SIGNAL
J2 7 CAL SENSE
J2 8 SHIELD
+ Excitation Power (RED)
- Excitation Power (BLACK)
+ Sense control
- Sense control
+ Signal Input from sensor (GREEN)
- Signal Input from sensor (WHITE)
Calibration Sensing Connection for Shunt
Case Shield for cable termination
J3 1 VDC COM - Signal Output Voltage Common
J3 2 V OUT SEL + Signal Output Voltage – Filter Select
J3 3 V OUT FAST + Signal Output Voltage – 1 kHz Filter
J3 4 4-20 mA COM Current Output Common
J3 5 4-20 mA OUT Current Output Signal
Page 7

M ODEL 3778 AC STRAIN GAGE PANEL METER
2 C ONNECTIONS
J1 - Sync Connections. The Sync connection is used when more than one 3778 or 3730
unit(s) are installed in an application that either the unit, cabling or the measurement
sensor are in close proximity to where "cross talk" or "drifting" of the measurement
occurs. To eliminate this condition; one 3778 unit should be declared the "Master" sync
clock unit and the other 3700 unit(s) should be configured for "Slave" mode to accept
the Sync pulse from the Master. Wiring is shown below. Note: When utilizing “Sync”
units must have the same excitation frequency setting. When using only two
instruments, different excitation frequency settings can be used to eliminate this
problem, if acceptable for the sensor that is connected to each instrument.
Fig. 4
Master 3778 Instrument
J1
Additional 3778 Instrument
(M/S ENABLE to LOG COM) Additional 3778 Instrument
(M/S ENABLE to LOG COM)
Master – Slave Sync Connections
When more than one 3778 instrument is being used in the
same measurement setup, beat frequencies can be
produced by the excitation clock oscillator circuit. To prevent
this, the user should declare one of the 3778 unit as the
Master and the other unit(s) should have M/S ENABLE tied
to LOG COM and wired as shown with the SYNC terminals
connected for the Master’s clock to Synchronize the Slave
units. Excitation frequency settings must be the same.
SYNC
LOG COM
M / S ENB
J1
SYNC
M / S ENABLE
J1
SYNC
M / S ENB
LOGIC COM
LOG COM
J1 – HOLD, TARE & REMOTE SHUNT CALIBRATION Logic Connections. These
connections are used when external control of the "HOLD" ,"TARE" or “± SHUNT CAL”
features of the unit are enabled or controlled by an external switch, PLC or relay. The
input Command signals are activated when connected to LOGIC COMMON and will affect
the display and analog output signals present on J3.
Fig. 5
J1 Logic Controls
HOLD Activates Analog HOLD when connected to LOGIC COMMON
TARE Activates Analog TARE when connected to LOGIC COMMON
TARE ENABLE Enables remote TARE and disables front panel TARE, when connected to LOGIC COMMON
LOGIC COMMON Connection to enable rear panel features
R CAL + Activates the Positive SHUNT Calibration when connected to LOGIC COMMON
R CAL - Activates the Negative SHUNT Calibration when connected to LOGIC COMMON
Push Button, Contact Relay,
Switch…..
LOG COM
HOLD TARE
TARE ENB
R CAL + R CAL -
Page 8

M ODEL 3778 AC STRAIN GAGE PANEL METER
2 C ONNECTIONS
J1 – Shunt Resistor Connections. Two terminal pins are provided via the J1 rear connector
for installation of an external shunt resistor. Terminal connections are used to install a user
defined resistor as determined by the sensor’s calibration data sheet or pre-determined by
the user. When an externally installed resistor is used, the ANALOG CONTROL switch 5 is
required to be in the External position (Switch 5 DOWN).
Note: The 3778 unit comes with an internally installed 59K Ohm resistor, as standard, and
enabled when the front panel ANALOG CONTROL Switch# 5 is in the Internal position
(Switch 5 UP).
Note: When a sensor has an integrated shunt resistor, the ANALOG CONTROL switch
setting needs to be in the External position and a shorting wire in place of the external
shunt resistor position. This provides the electrical path for the Calibration Sense line to
enable the sensor’s internal shunt resistor when the + or – Shunt Calibration rear terminals
or push buttons are activated.
SHUNT Resistor – User Provided
(Note: ANALOG CONTROL switch
5 must be in the External position)
External Shunt Resistor Connections
J1
SYNC
M / S ENABLE
TARE ENABLE
HOLD
TARE
LOGIC COM
R CAL +
R CAL -
SHUNT RESISTOR
SHUNT RESISTOR
NOTE: Daytronic Shunt Calibration circuit, when activated, will place the Shunt resistor across
the + Sense Line (for positive shunt) or the – Sense Line (for negative shunt) with the
connection of the Sensor’s Calibration Sense line located on the J2 connector - which is
recommend to be connected to the + Signal line. When not activated, the Calibration Sense line
is buffered as to not affect the sensor’s operational characteristics. If Shunt calibration (when
not activated) needs to be reference to ground, which is the case specified for some transducers,
then a jumper connection needs to be installed via the front panel as shown below next to the
Coarse Zero adjustment. This connection will reference the shunt circuit correctly to conform to
the transducer’s certified calibration document.
Page 9

M ODEL 3778 AC STRAIN GAGE PANEL METER
2 C ONNECTIONS
Fig. 7 Model 3778 Transducer Cabling - AC Strain Gage (8 wire)
+ SENSE
- SENSE
+ EXCITATION
- EXCITATION
+ SIGNAL
SHIELD
- SIGNAL
CAL SENSE
EXCITATION EXCITATION
SENSE
SENSE
SIGNAL
SIGNAL
CAL SENSE
+
_
_
_
++
SHIELD
Model 3778 Transducer Cabling – Rotary Torque w/ External Shunt Pin
(-EXCITATION)
(+SENSE)
(-SENSE)
(+EXCITATION)
DAYTRONIC
(+SIGNAL)
(-SIGNAL)
(CAL SENSE)
(SHIELD)
-SIG
-EXC
+EXC
(ROTOR) (STATOR)
EXC B+Excitation
N/C
TRANSDUCER
CONNECTOR
SIG
C
E
D
Rotary Torque Sensor Wiring Example
RED
BLK
WHT
GRN
N/C
SIG+
SHUNT
SHORTED
- CAL + CAL
- CAL – SHUNT NEGATIVE
+ CAL – SHUNT POSITIVE
A
- Excitation
+Excitation Sense
- Excitation Sense
+ Signal
- Signal
Calibration Sense
Note: Cable should below capacitance, low resistance – Four Twisted pair, shielded cable. Paired as shown.
Recommended Cable - Daytronic Part # 77029.00 or Belden 8164
For proper operation, sense lines must be connected at the transducer or at the rear panel of the
3778. It is recommended, if cabling is greater than 20 feet to use the eight wire configuration.
Page 10
WARNING
Qualified personnel who work on or near exposed energized electrical conductors must follow applicable safety
related work practices and procedures including appropriate personal protective equipment in compliance with the
Standard for Electrical Safety Requirements for Employee Workplaces (ANSI/NFPA 70E-2012) of USA and any
additional workplace safety requirements applicable to your installation.

M ODEL 3778 AC STRAIN GAGE PANEL METER
2 C ONNECTIONS
J3 - Analog Connections. Connections are used to provide analog outputs from the meter's
signal conditioning area in the form of ± 5VDC or ±10 VDC (selectable via the front panel
controls) and 4-20 mA (or selectable 4-12-20 mA).
12345
Analog Voltage Output
+/- 5 Vdc or +/- 10 Vdc with
fixed cutoff filter @ 1 KHz
Analog Voltage Output
+/- 5 Vdc or +/- 10 Vdc with
front panel selectable filter
@ 2/20/200 Hz
Analog Current Output
4-20mA, 4-12-20mA
at selected cutoff filter
+ SIGNAL
- SIGNAL
- SIGNAL
+ SIGNAL
+ SIGNAL
- SIGNAL
Analog Output Connections
VDC COM - Pin 1 Voltage Common (- Signal out); Negative reference for Pin 2 and Pin 3
Voltage Output of the amplified analog signal.
V OUT SEL - Pin 2 Voltage Output Selected (+Signal out) reference to Pin 1. The Full Scale
Voltage is determined by the position of switch 1 -VDC on the Conditioner
Controls. Voltage Filter output response of this signal is determined by the
position of switch 3 –FIL and 4 –FIL on the Analog Controls.
V OUT FAST - Pin 3 Voltage Output Fast. (+ Signal out) reference to Pin 1. Full Scale Voltage is
determined by the position of switch 1 -VDC of the Conditioner Controls.
Filter response is fixed at the highest analog signal response of 1 KHz.
4-20mA COM - Pin 4 4 - 20 mA Current Output Common (- Signal) reference for Pin 5 Current
Output.
4-20mA OUT - Pin 5 4 - 20 mA Current Output (+Signal) reference to Pin 4 Current Output
Common. Mode of the Current Output is selectable for 4 - 20 mA or 4-12-20
mA as determined by the position of switch 2 -mA of the Conditioner Control
switch(s) on the Front Panel.
Page 11

M ODEL 3778 AC STRAIN GAGE PANEL METER
3 C ONTROLS
Digital Display Range and Decimal Point Selection
Configures the Engineering Unit Digital Display Range. Three selections are available to set the display
operation for 1 count in 5000, 2 counts in 10000 or 5 counts in 20000 resolution. These full scale display
ranges correspond to the analog output full scale value of ±5 VDC or ± 10 VDC as selected via the analog
controls and when the Display Span control is set to the “OFF” position (see below).
Switch 1 - selects decimal point for position X.XXXXX
Switch 2 -
selects decimal point for position XX.XXXX
Switch 3 -
selects decimal point for position XXX.XXX
Switch 4 -
selects decimal point for position XXXX.XX
Switch 5 -
enables dummy zero display digit XXXXX0
Switch 6 & 7 -
selects Display Full Scale Range.
Display Span Adjustments
Used to adjust the digital readout of the 3778 meter independent of the analog signal when not
in the “OFF” position. After setting the analog output signal level, the user rotates the Display
SPAN “C” Coarse controls and adjust the Display “F” (fine) control for proper engineering
units display.
Example: if the unit is connected to a 750.0 in/Lb. transducer – adjust the analog output for
maximum full scale analog output. Once achieved, rotate the Display “C” control from “OFF” to
approximately 750.0 on the display. Use the Display SPAN “F” control for fine adjustment of the readout for
the 750.0 reading on the display.
Display Coarse Span -
16 position switch to adjust wide display span / gain authority
Display Fine Span -
25 Turn potentiometer for fine span / gain control of display reading
Display “OFF” – switch position “F” – “OFF” which disables the Display Span feature
Page 12

M ODEL 3778 AC STRAIN GAGE PANEL METER
3 C ONTROLS (cont.)
Analog Control Settings
Analog Control - 7 position dip switch configures the main parameters of the AC Signal
conditioner for excitation frequency, mode of the analog output signal, low pass filter
characteristics and internal or external shunt selection.
1 – 5 VDC Output - UP sets the analog output FSto 5 VDC, DOWN is 10 VDC
2 – 4 - 20 mA - UP sets the analog current output for 4-20 mA , DOWN is 4-12-20ma
3 – 20/200 Hz - UP selects 20 Hz filter. DOWN selects 200 Hz filter
4 – 20/2 Hz - UP selects 20 Hz filter. DOWN selects 2 Hz filter
5 – Shunt - UP selects the Internal Shunt, DOWN is External
6 – Excitation Frequency - UP selects 3.28KHz,DOWN 5.0 KHz
7 – Not Used
With all of the switches in the up position, the unit will have the following settings:
3.28KHz Excitation frequency
The full scale analog output will be 5.000 VDC
•The current output will be set for 4 ma = zero and 20 ma will = positive full scale
The selected analog output - low pass filter will be set for 20 Hz
•Internal SHUNT resistor of 59K is selected.
Analog Control Settings for Conditioner Configuration
1 - VDC OUT
2 - mA OUT
3 - FILTER
4 - FILTER
5 - SHUNT
6 - EXC FRQ
7 - N/A
5
4-20
20 Hz
20 Hz
INT
3.28
10
4-12-20
200 Hz
2 Hz
EXT
5.0
Down
Function
Analog Control Settings (red switch array)
The selection of the 7 front panel analog control
settings will configure the signal conditioning
section of the meter. The position of the switches
will depend on the type of sensor, its parameters
and the expected analog output signal levels
along with the analog output signal’s 3db roll-off
response characteristics.
Page 13

M ODEL 3778 AC STRAIN GAGE PANEL METER
3 C ONTROLS (cont.)
Analog Wide Gain and Wide Zero Controls
Rotary range control switches for setting of the gain of the analog output signal of the 3778
meter. Each control step will in turn affect the digital readout for engineering unit’s
adjustments.
Wide Zero - 16 position switch to adjust wide zero authority, approx. 13% / position
Wide Span -
16 position switch to adjust wide sensor gain ranges
Fine Analog Zero and Span Adjustments
Potentiometer controls for the fine adjustment of the gain and zero settings of the analog
output signal of the 3778 meter. These controls are present when the front panel is re-installed
and are used for fine re-adjustment of the sensor’s calibration measurement.
Coarse Zero - 22 Turn potentiometer adjustment for balance control of the analog signal
Fine Zero -25 Turn potentiometer for fine balance control of the analog signal
Coarse Span - 22 Turn potentiometer adjustment for the analog control of gain
Fine Span -25 Turn potentiometer adjustment for the analog control of fine gain
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M ODEL 3778 AC STRAIN GAGE PANEL METER
3 C ONTROLS (cont.)
Analog Symmetry, Phase, ± CAL, TARE
SYM Symmetry - Adjust the negative gain slope for symmetrical analog adjustment as
referenced to the positive span value. 20 Turn potentiometer, with approx. ± 2% authority
Phase – Used to compensate for cable and sensor characteristics to allow synchronization
of the return signal phase to the excitation phase. 20 Turn potentiometer, with approx. +/-
35 Degrees authority
+ CAL Calibration Positive Shunt - Push switch, when depressed connects the Internal or
External (as selected) Shunt resistor across + SENSE and CAL SENSE
- CAL Calibration Negative Shunt - Push switch, when depressed connects the Internal or
External (as selected) Shunt resistor across - SENSE and CAL SENSE
TARE Tare - Push / Push switch. When active, offsets the present sensor signal input
to "Zero". When activated, a green LED light will illuminate, during activation process,
LED will light Yellow. If disabled, or out of range, LED will be RED. TARE maybe
remotely activated via rear J2 connections. Front panel TARE can be disabled via J2 Pin 4
being connected to Logic Common, Pin 3.
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M ODEL 3778 AC STRAIN GAGE PANEL METER
4.CALIBRATION – 2 Point - Dead Weight with known input
This section contains the instructions for calibrating the 3778. Reference the description of the instrument
front-panel (see Page 1). To perform calibration, proceed as follows.
(a) Connect Power, Sensor and Analog terminals as required. Apply power. The front-
panel digital display should light indicating the application of the AC input power. Allow
10 minutes of warm up for stabilization of transducer characteristics. Remove the front
panel cover of the 3778 unit which is held in place by the two small Phillips screws.
(b) Position the front panel switches to the desired settings for the application. Refer to Section 3
for details. Insure TARE is not engaged.
(c) Center the Zero and Span potentiometers as needed by rotating the potentiometers fully CW
(Coarse is 22 turns, Fine is 25 turns), then reverse direction - CCW (Coarse 11 turns and Fine 13
turns) to obtain mid-authority of the controls. Typically this is done on initial calibration. When
recalibrating for minor adjustments this may not be required.
(d) With mechanical Zero or Balance established at the transducer (transducer “relaxed”); Adjust
Wide Zero then Coarse Zero and then Fine Zero for the Zero position reading on the display or
the desired analog output signal. Note: Display can be adjusted independently to the analog
signal when the Coarse Display control is not in the “OFF” position.
(e) Apply a known span reference standard (dead weight torque / load) so the sensor is greater than
50% of the positive full scale (or preferred - the “nominal” operating value of the transducer).
Adjust the Wide Span then Coarse Span and then the Fine Span to obtain an approximate display
or analog value for the instrument. Once this level is establish, Adjust the 3778 Phase control to
obtain the highest magnitude on the display. This “peak” or “hump” will synchronize the
Excitation phase with the return Signal Phase for proper operation of the 3778 unit. Once Phase
has been accomplished, the 3778 will not need to be re-phased for subsequent calibrations unless
the cable or the transducer is replaced. Re-establishment of Wide Span may be needed if the
phase adjustment causes display saturation.
(f) Return the sensor to the Zero position in step (d) and re-adjust the Zero controls as needed to
obtain the proper reading (or analog signal) for the application’s zero position.
(g) Apply a known full scale Load to the sensor. Preferably in the positive direction. This should
represent the “nominal” working level of the sensor. Re-Adjust the Coarse Span and Fine Span
controls, as needed, for precise engineering units reading on the display as well as the analog
output desired.
(h) Repeat Steps (f) and (g) to obtain proper measurement readings since the Gain – Span
controls will affect the Zero amplification of the input signal.
(i) Once completed, if the sensor is going to be utilized in the Negative or CCW mode, it is
recommended to reverse the dead weight Load on the sensor to a known “negative” load and
adjust the Symmetry control for a proper symmetrical reading of the sensor input. Note the
Symmetry control affects the Negative Span for approx. ± 2% of full scale adjustment control.
(j) Re-install the front panel. Fine Span and Zero controls are accessible with front panel installed.
(k) Use the + CAL and – CAL buttons to activate positive or negative shunt for future reference
purposes as a means of verification of the calibration. Sensor should be in the zero or relaxed
position when performing Shunt calibration activation.
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M ODEL 3778 AC STRAIN GAGE PANEL METER
4. CALIBRATION – Shunt Calibration
This section contains the instructions for calibrating the 3778 using the Shunt calibration method.
Note: To calibrate the 3778, a known nominal load should be used to properly adjust the Phase control
prior to establishing a Shunt calibration for the measurement system.
(a) Connect Power, Sensor and Analog terminals as required. Apply power. The front-panel digital
display should light indicating the application of the AC input power. Allow 10 minutes of warm
up for stabilization of transducer characteristics. Remove the front panel cover of the 3778 unit
which is held in place by the two small Phillips screws.
Note: The 3778 unit has an internal 59K Shunt resistor installed within the unit. If a different
resistor or resistor value is to be used to correspond to the transducer’s calibration sheet; install the
resistor on the rear terminal provided and place the Analog Control switch 5 to External. See page
9.Shunt calibration is only active if the CAL Sense line is connected to the + Signal line. For
transducers with an internal shunt resistor: 1.) Cal Sense should be attached to the transducer’s
shunt activation connector pin; 2.) External Shunt selected on the Analog Controls; 3.) A shorting
wire is installed in place of the External Shunt resistor terminals on the rear of the unit.
(b) Position the front panel switches to the desired settings for the application. Refer to Section 3 for
details.
(c) Center the Zero and Span potentiometers as needed by rotating the potentiometers fully CW
(Coarse is 22 turns, Fine is 25 turns), then reverse direction - CCW (Coarse 11 turns and Fine 13
turns) to obtain mid-authority of the controls. Typically this is done on initial calibration. When
recalibrating for minor adjustments this may not be required.
(d) With mechanical Zero or Balance established at the transducer (transducer “relaxed”); Adjust
Wide Zero then Coarse Zero and then Fine Zero for the Zero position reading on the display or
the desired analog output signal. Display can be adjusted independently to the analog signal.
(e) Apply a known span reference standard (dead weight torque / load) so the sensor is greater than
50% of the positive full scale (or preferred - the “nominal” operating value of the transducer).
Adjust the Wide Span then Coarse Span and then the Fine Span to obtain an approximate display
or analog value for the instrument. Once this level is establish, Adjust the 3778 Phase control to
obtain the highest magnitude on the display. This “peak” or “hump” will indicate the
synchronization of the Excitation phase angle with the Signal Phase angle for proper operation of
the 3778 unit. Once Phase has been accomplished, the 3778 will not need to be re-phased for
subsequent calibrations unless the cable or the transducer is replaced.
(f) Return the sensor to the Zero position in step (d) and re-adjust the Zero controls as needed to
obtain the proper reading (or analog signal) for the application’s zero position.
(g) Depress and hold the + CAL button while adjusting the Coarse Span and Fine Span controls, as
needed, for precise engineering units reading on the display as determined by the sensor’s
calibration sheet or other reference data (see Equivalent Input shunt calculation below).
(h) Repeat Steps (f) and (g) to obtain proper measurement readings since the Gain – Span controls
will affect the Zero amplification of the input signal.
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M ODEL 3778 AC STRAIN GAGE PANEL METER
4. CALIBRATION(cont.) – Shunt Calibration
(i) Once completed, if the sensor is going to be utilized in the Negative or CCW mode, depress and
hold the – CAL button and adjust the Symmetry control for a proper symmetrical reading of the
shunt input as noted on the sensor’s calibration data sheet. Note the Symmetry control affects the
Negative Span for approx. ± 2% of full scale adjustment control.
(j) Release the Cal button and adjust Zero as needed. Re-install the front panel to the instrument.
Minor adjustments and controls are assessable via the front of the unit.
Shunt Resistor Calculation
If dead weight calibration is not practical and the transducer calibration data is unknown, the
Equivalent Input value for the factory-installed calibration resistor can be approximated as follows,
assuming that the mv/v sensitivity rating of the transducer and the bridge resistance are known.
X = 25000 x Rb
K x Rc
Where X = Equivalent Input, % of full scale
Rb = bridge resistance, ohms
K = transducer sensitivity, mv/v full scale
Rc = calibration resistance, ohms (59 K installed)
Sample Calculation: Assume that K = 3.000 mv/v for a 5000-pound load cell (full scale) with a bridge
resistance of 350 ohms and using the internal 59K Ohm shunt.
25000 x 350
59000 x 3 = 49.44% of full scale = 2472 pounds
Per this example, when the + CAL switch is depressed, the reading should be 2472, with the sensor at
no load.
Display Calibration The 3778 instrument display has separate adjustment controls that are
independent of the analog controls. This allows the user to alter the display reading to a value that is
suited for the engineering units display reading required while maximizing the analog output signal.
In a standard – default “OFF” switch position of the Display Coarse Span control, the display has a
full scale reading set by the display range switches of 5000, 10000 or 20000 counts. At the selected
reading, the full scale analog output signal will be 5 VDC or 10 VDC, as selected via the analog
controls.
To accomplish the display adjustment change, the user would first set the desired display range and
decimal location using the display dip switches, adjust the analog output to the desired level and then
adjust the Display Coarse and Fine span controls for the required digital readout. Returning the
Display C (coarse) control to the designated “OFF” position will return the display to the default
condition as described above.
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M ODEL 3778 AC STRAIN GAGE PANEL METER
4. CALIBRATION (cont.)
Master/Slave Connections.
When more than one 3778 is being used in a measurement setup
(instruments are closely mounted or the transducer cabling is in a common conduit or raceway),
beat frequencies may be produced from the oscillators used in the instruments to develop the
excitation. To prevent beat frequencies from occurring, one unit can be designated the master, and
the remaining units can be driven from the oscillator contained in the master unit. The remaining
units are designated as slave instruments. To perform master/slave wiring, refer to Section 2.
Phase & Signal Reversal: The phasing signal is derived from the excitation circuit. Therefore
when doing signal reversal, (+ to -, or CW to CCW) it must be accomplished by reversing the
signal leads, not the excitation & sense leads from the transducer to the conditioner.
Tech Tip: The inability to balance correctly where the unit output reads totally off scale and the zero
controls have no authority can very likely be the result of a damaged or defective transducer or
cable. This possibility can be confirmed (or eliminated) by substituting a transducer and cable
known to be in good condition or by simulating a balanced transducer, using either a
commercially available transducer simulator or the simple star bridge arrangement shown below.
The star bridge simulates a conventional four-arm bridge in an exact condition of balance. To
construct a star bridge connect four resistors as shown; use 180-ohm resistors to approximate a
350-ohm bridge. Neither the resistor values nor temperature characteristics are critical. Solder two
excitation resistors together, and then solder the two Signal resistors together. Next, connect the
two junctions together using a separate wire as shown. There is a good reason for this method of
construction, and it should be followed. Connect the substitute or simulated transducer to the
module I/O connector using a short 4-wire cable configuration as shown in Figure 4. Attempt to
balance the substitute or simulated transducer. If conditions now appear to be normal, the
transducer or cable is at fault. If the previous difficulties persist, the meter is at fault.
Star-Bridge Construction
Page 19