YOKOGAWA JUXTA VJAK User manual

User’s
Manual
1
Thank you for purchasing the JUXTA Signal Conditioner.
Please read through this manual before use for correct handling.
2-9-32, Naka-cho Musashino-shi, Tokyo 180-8750 Japan
http://www.yokogawa.com/ns/juxta/im/
You can download the latest manuals from the following website:
IM 77J01A21-01E
3rd Edition June 2022 (YK)
CAUTIONARY NOTES FOR SAFE USE OF THE
PRODUCT
This User’s Manual should be carefully read before installing
and operating the product. Please keep this User’s Manual for
future reference. For more information of the safety precautions,
please refer to the “Precautions on the Use of the JUXTA Series (IM
77J01A00-91Z1)”.
The related manuals and general specications
are shown in the table below.
Doc. Name Doc. Number
Precautions on the Use of the JUXTA Series (User’s Manual) IM 77J01A00-91Z1
Model VJAK Limit Alarm for DC Current Input (User’s
Manual)
IM 77J01A21-01E
(This manual)
Model VJAK Limit Alarm for DC Current Input
(General Specifications)
GS 77J01A21-01E
User’s manuals in the above table are essential parts of the
product; keep it in a safe place for future reference.
This manual is intended for the following personnel;
• Engineers responsible for installation, wiring, and maintenance
of the equipment.
• Personnel responsible for normal daily operation of the
equipment.
The following symbol is used on the product and in this manual to
ensure safe usage.
WARNING
Calls attention to actions or conditions that could
cause serious or fatal injury to the user, and indicates
precautions that should be taken to prevent such
occurrences.
CAUTION
Calls attention to actions or conditions that could
cause injury to the user or damage to the instrument
or property and indicates precautions that should be
taken to prevent such occurrences.
QR Code
The product has a QR Code pasted for e󰀩cient plant
maintenance work and asset information management.
It enables conrming the specications of purchased products
and user’s manuals.
For more details, please refer to the following URL.
https://www.yokogawa.com/qr-code
* QR Code is a registered trademark of DENSO WAVE
INCORPORATED.
CHECKING THE PRODUCT SPECIFICATIONS
AND THE CONTENTS OF PACKING
(1)ModelandSpecicationsCheck
Check that the model and specications indicated on the nameplate
attached to the side face of the main unit are as ordered.
(2) Contents of the Packing
Check that the package contains the following items:
• VJAK: 1
Standard Accessories:
• Tag number label: 1 sheet
• User’s manual (IM 77J01A21-01E, this manual): 1 copy
• User’s manual (IM 77J01A00-91Z1): 1 copy
GENERAL
This plug-in type Limit Alarm for DC current input receives 4 to
20 mA DC current signal. It is used in combination with two-wire
type transmitter.
• Each parameter setting can be changed using a PC (VJ77
PC-based Parameters Setting Tool).
MODEL AND SUFFIX CODES
Model Su󰀩xcodes Description
VJAK -0 2 x-A T 0 0 /x
Limit Alarm for DC Current Input
Fixed
code -0 Always -0
Output
conguration 22 outputs
Power supply 6100-240 V AC/DC*1
715-30 V DC*2
Input signal -A
4 to 20 mA DC
(Transmitter power supply:
25.25 ± 0.25 V DC)
Output signal TAlarm output (2 relay contacts)
Fixed code 0Always 0
Fixed code 0Always 0
Option
/SN No socket (with socket if not
specied)
/C0 HumiSeal coating
/FB Fuse bypass
*1: Operating range: 85 to 264V AC/DC
*2: Operating range: 12 to 36V DC
*3: DC voltage signal or DC current signal
1. MOUNTING METHODS
CAUTION
●Plug/disconnect the main unit into/from the
socket vertically to the socket face. Otherwise the
terminals may bend and it may cause bad contact.
●The converter shall not tilt 5 degrees or more in
either direction when installed.
●When the converter is not connected to the socket,
it is necessary to protect the socket against ingress
of dust to the connector part.
●Keep this product in a conductive bag when
plugged out, during transport or storage.
Model VJAK
Limit Alarm
for DC Current Input

2IM 77J01A21-01E 3rd Edition
1.1 Wall Mounting
Loosen the main unit-xing screw to disconnect the main unit
from the socket. Next, anchor the socket onto the wall with
screws. Then, plug the main unit into the socket and secure the
main unit with the main unit-xing screw.
Main
unit-fixing
screw
Socket
Main unit
Hole for main
unit-fixing screw
Mounting
screws
<Mounting Dimensions>
Unit: mm
29.5 or more
22±0.2
59±0.3
2-M4 or
2-ø4.5 or more
1.2 DIN Rail Mounting
Locate the VJAK so that the DIN rail ts into the upper part of the
DIN-rail groove at the rear of the socket, and fasten the socket
using the slide lock at the lower part of the socket.
DIN
rail
Fit into
here
Push
DIN rail
(Rear of the socket)
Slide lock
DIN rail
1.3 Mounting Using a Multi-mounting Base
For mounting using a multi-mounting base, see the Instruction
Manual for VJCE (VJ Mounting Base).
1.4 Using a Duct
Wiring duct should be installed at least 30 mm away from the top
and bottom faces of the main unit.
2. INSTALLATION LOCATIONS
• Avoid the following environments for installation locations:
Areas with vibrations, corrosive gases, dust, water, oil,
solvents, direct sunlight, radiation, a strong electric eld,
and/or a strong magnetic eld, direct radiant heat, wind,
temperature uctuation, 2,000 m or more above sea level.
• If there is any risk of a surge being induced into the power line
and/or signal lines due to lightning or other factors, a dedicated
lightning arrester should be used as protection for both the
product and a eld-installed device.
• Operating temperature/humidity range: -10 to 55°C (-10
to 45°C for side-by-side mounting*)/5 to 90%RH (no
condensation)
* If the previous model (style S3.xx earlier) is installed
together, the ambient temperature is 0 to 40°C.
• Continuous vibration: (at 5 to 9 Hz) Half amplitude of 3 mm or
less (at 9 to 150 Hz) 9.8m/s2or less, 1 oct/min for 90 minutes
each in the three axis directions
• Impact: 98 m/s2 or less, 11 ms, 3 axes, 6 directions, 3 times
each
3. EXTERNAL WIRING
WARNING
●Toavoidtheriskofanelectricshock,turno󰀨the
power supply and use a tester or similar device to
ensure that no power is supplied to a cable to be
connected, before carrying out wiring work.
●Do not operate the product in the presence of
ammableorexplosivegasesorvapors.Todosois
highly dangerous.
●Useoftheproductignoringthespecicationsmay
cause overheating or damage. Before turning on
the power, ensure the following:
•Power supply voltage and input signal value
applied to the product should meet the required
specications.
•The external wiring to the terminals and wiring to
ground are as specications.
Wiring should be connected to the terminals on the socket of the
VJAK. The terminals for external connections are of M3 screws.
Use crimp-on lugs for connections to the terminals.
• It is recommended that signal wires have a nominal cross-
sectional area of 0.5 mm2or thicker, while the power cable has
a nominal cross-sectional area of 1.25 mm2or thicker.
1011
3 2 1
4
56
789
3
1
3
1
44
11
10
8
5
2
9
7
GND
L
+
N –
COM
ALM2 (NO)
COM
COM
ALM1 (NO)
COM
PS
+
Input signal
+
–
+
–
––
When using
internal
power supply
When using
external
power supply
Power supply
Alarm-1 output signal
Alarm-2 output signal
When connecting the transmitter to the VJAK directly without using the transmitter
power supply, connect [+] of the transmitter output to the terminal no. 3 and connect [
–
]
to the terminal no. 4.
CAUTION
●The product is sensitive to static electricity;
exercisecareinoperatingit.Beforeyouoperate
the product, touch a nearby metal part to discharge
static electricity.
●Ifaninductance(L)loadsuchasauxiliaryrelaysor
solenoid valves is used, always insert a spark killer
fordiminishingsparks,suchasaCRlteroradiode
in parallel with the inductance load. Otherwise a
malfunction or relay failure may occur. Refer to the
following guidelines for a capacitor and resistor:
Capacitor : 0.5 to 1 μF with respect to a contact current
of 1 A
Resistor: 0.5 to 1 Ω with respect to a contact voltage of
1 V
●The power line and input/output signal lines should
be installed away from noise-generating sources.
Otherwise accuracy cannot be guaranteed.
●Make sure to earth ground the ground terminal
through minimum resistance. The length and
thickness of the grounding cable should be as
short and thick as possible. Directly connect the
lead from the ground terminal (terminal no. 8) of
the product to the ground. Do not carry out daisy-
chained inter-ground terminal wiring.
●If the ambient temperature is 50 °C or more, please
use the cable that the rated temperature is 70 °C or
more.
4. DESCRIPTION OF FRONT PANEL AND
CONNECTION OF SETTING TOOLS
4.1 Front Panel
The communications connector on the front panel is used for
setting up parameters using a PC (VJ77 PC-based Parameters
Setting Tool) or the Handy Terminal (JHT200). The alarm indicator
lamps for alarm 1 and alarm 2 light up if an alarm occurs.
Alarm indicator lamp
(for alarm 1)
Communication connector
Alarm indicator lamp
(for alarm 2)

3IM 77J01A21-01E 3rd Edition
4.2 Connecting the Setting Tools
Used to set JUXTA parameters on a PC (VJ77 Parameter Setting
Tool).
PC
JUXTA
VJ series
Modular-jack
conversion
adapter
Dedicated adapter for VJ77
(L4506HA)
Micro USB (USB2.0) cable
• Use the VJ77 of version R2.02.01 or later.
5. SETTING PARAMETERS
Set the parameters using a PC (VJ77 PC-based Parameters
Setting Tool). Refer to the list of parameters in this manual and
the user’s manual for VJ77 PC-based Parameters Setting Tool
(IM 77J01J77-01E).
5.1 Settings Related to Input
5.1.1 SquareRootExtractionFunction
Select SQR in [D41: LINEARIZE] to set “with square root
extraction function.”
5.1.2 Low-cut Function
Set the low-cut point in [D42: LOW CUT] numerically when
“with square root extraction function” is set.
• Setting range: 0 to 100% of input range
• Setting resolution: 0.1%
Input signal (X)
Output signal
(Y)
0
Low-cut point
Hysteresis
(0.2% fixed)
Y=X
5.1.3 Software Filter
Set the software lter in [D57: S/W FILTER].
OFF, LOW, MIDDLE, HIGH (default value: OFF)
When LOW, MIDDLE, or HIGH is selected, a rst-order lter
equivalent to 100 ms, 300 ms, or 1 s is inserted in the input.
5.2 Settings Related to Alarm Output
5.2.1 Alarm Setpoint
Set the alarm setpoints of alarm 1 and alarm 2 in [E03: SET
POINT1] and [E04: SET POINT2] numerically.
• Setting range: 0 to 100% of input range
• Setting resolution: 0.1%
5.2.2 Direction of Alarm Action
Select the direction of alarm-1 action and that of alarm-2
action from among HIGH ALM (high-limit alarm) and LOW
ALM (low-limit alarm) in [E05: ALM1 ACTION] and [E06:
ALM2 ACTION].
• To activate alarm status when input signal ≥ alarm setpoint,
select HIGH ALM.
• To activate alarm status when input signal ≤ alarm setpoint,
select LOW ALM.
5.2.3 Hysteresis
Set the alarm-1 and alarm-2 hysteresis in [E09:
HYSTERESIS1] and [E10: HYSTERESIS2]. Hysteresis is a
value added to the alarm setpoint in order for an alarm status
to be released (to normal) after the alarm status has been
activated. The alarm status will be released in the following
conditions, depending on the direction of alarm action.
* When HIGH ALM (high-limit alarm) is set: Alarm is released
when input signal < (alarm setpoint - hysteresis).
* When LOW ALM (low-limit alarm) is set: Alarm is released
when input signal > (alarm setpoint + hysteresis).
• Setting range: 0 to 100% of input range
• Setting resolution: 0.1%
5.2.4 Alarm ON Delay and Alarm OFF Delay
Set the alarm-1 and alarm-2 ON delays in [E11: ON DELAY1]
and [E12: ON DELAY2] and then alarm-1 and alarm-2 OFF
delays in [E13: OFF DELAY1] and [E14: OFF DELAY2].
An alarm ON delay is the condition monitoring time from the
establishment of alarm conditions to its output; an alarm OFF
delay is the condition monitoring time from the establishment
of return-to-normal conditions to its output.
• Setting range: 0 to 999 seconds
• Setting resolution: 1 second (However, about 0.2 second is
to be added to the set time to prevent wrong operation.)
For example, when an alarm ON delay is set to 1 second,
alarm output is generated if alarm status continues for 1
second or more after the input value exceeds the alarm
setpoint. Further, when an alarm OFF delay is set to 2
seconds, alarm output is released if normal condition
continues for 2 seconds or more after the input value has
returned to normal from the alarm status.
5.2.5 Direction of Relay Action
Select the direction of relay energizing in alarm-1 normal
condition and alarm-2 normal condition from among NRM DE-
ENERGIZED (de-energized under normal condition) and NRM
ENERGIZED (energized under normal condition) in [E15: RL1
ACTION] and [E16: RL2 ACTION].
6. DESCRIPTION OF ALARM ACTIONS
This chapter describes examples of alarm actions under the
following conditions.
Item Alarm 1 Alarm 2
Parameter Setpoint Parameter Setpoint
Direction of
alarm action
E05 : ALM1
ACTION
High-limit
alarm
E06 : ALM2
ACTION
Low-limit
alarm
Alarm
setting
E03 : SET
POINT1 80% E04 : SET
POINT2 15%
Hysteresis E09 :
HYSTERESIS1 10% E10 :
HYSTERESIS2 5%
Alarm ON
delay
E11 : ON
DELAY1 1 sec E12 : ON DELAY2 3 sec
Alarm OFF
delay
E13 : OFF
DELAY1 2 sec E14 : OFF
DELAY2 4 sec
Description
of alarm
actions
The alarm is output if the
condition where the input
value is 80% or more of
high-limit alarm continues
for 1 second or more.
After the alarm is output,
when the condition where
the input value is less than
70% of high-limit alarm
continues for 2 seconds or
more, the status returns to
normal.
The alarm is output if the
condition where the input
value is 15% or less of low-
limit alarm continues for 3
seconds or more.
After the alarm is output,
when the condition where the
input value is more than 20%
of low-limit alarm continues
for 4 seconds or more, the
status returns to normal.

4IM 77J01A21-01E 3rd Edition
[%]
0
20
15
40
60
80
100 [1] [2]
[3] [4]
1 sec 2 sec
3 sec 4 sec
Alarm-2 hysteresis (5%)
Alarm-1 hysteresis (10%)
Alarm-1 setpoint (80%)
Alarm-2 setpoint (15%)
Elapsed time sec
Alarm-1 ON delay Alarm-1 OFF delay
Alarm conditions established Alarm conditions established Normal conditions established Normal conditions established
Low-limit alarm ON Low-limit alarm OFF
Alarm-2 ON delay Alarm-2 OFF delay
[1]: Alarm status does not continue for more than 1 second after the
alarm conditions are established at alarm 1.
[2]: Normal status does not continue for more than 2 seconds after the
normal conditions are established at alarm 1.
[3]: Alarm status does not continue for more than 3 seconds after the
alarm conditions are established at alarm 2.
[4]: Normal status does not continue for more than 4 seconds after the
normal conditions are established at alarm 2.
Alarm conditions established Alarm conditions established
High-limit alarm ON High-limit alarm OFF
Normal conditions established Normal conditions established
Alarm-1 action
Alarm-2 action
Alarm
Normal Normal
Normal Alarm Normal
7. LIST OF PARAMETERS
DISPLAY ITEM
MODEL Model
TAG NO Tag No.
SELF CHK Self-check result
A DISPLAY1 Display 1
A01 INPUT1 Input value 1
A09 OUTPU1 Output value 1
A15 ALM1 STATUS Alarm-1 status
A16 ALM2 STATUS Alarm-2 status
A54 STATUS Status *1
A56 REV NO Rev No.
A58 MENU REV Menu Rev
A60 SELF CHK Self-check result
B DISPLAY2 Display 2
B01 INPUT1 Input value 1
B09 OUTPUT1 Output value 1
B15 ALM1 STATUS Alarm-1 status
B16 ALM2 STATUS Alarm-2 status
B60 SELF CHK Self-check result
D SET (I/O) Setting (I/O)
D01 TAG NO.1 Tag no.1
D02 TAG NO.2 Tag no.2
D03 COMMENT1 Comment 1
D04 COMMENT2 Comment 2
D41 LINEARIZE Linearize
D42 LOW CUT Low cut
D57 S/W FILTER Software lter
D59 NMRR Frequency setting *2
D60 SELF CHK Self-check result
E SET(ALM) Setting (alarm output)
E03 SET POINT1 Alarm-1 setting (%)
E04 SET POINT2 Alarm-2 setting (%)
E05 ALM1 ACTION Direction of alarm-1 action
E06 ALM2 ACTION Direction of alarm-2 action
E09 HYSTERESIS1 Alarm-1 hysteresis
E10 HYSTERESIS2 Alarm-2 hysteresis
E11 ON DELAY1 Alarm-1 ON delay setting
E12 ON DELAY2 Alarm-2 ON delay setting
E13 OFF DELAY1 Alarm-1 OFF delay setting
E14 OFF DELAY2 Alarm-2 OFF delay setting
E15 RL1 ACTION
Direction of alarm-1 relay action
E16 RL2 ACTION Direction of alarm-2 relay action
E60 SELF CHK Self-check result
P ADJUST Adjustment
P04 IN1 ZERO ADJ Zero adjustment of input-1
P05 IN1 SPAN ADJ Span adjustment of input-1
P60 SELF CHK Self-check result
Q TEST Test
Q10 ALM1 TEST Forced output (alarm 1)
Q11 ALM2 TEST Forced output (alarm 2)
Q60 SELF CHK Self-check result
*1 The status is displayed for service personnel to see
history records.
*2 The parameters are the items to be set at the factory.
8. MAINTENANCE
The product enters the operable status as soon as the power is
turned on, but requires 10 to 15 minutes of warm-up to meet the
performance requirements.
8.1 Calibration Apparatus
• A voltage and current generator (YOKOGAWA GS200 or the
equivalent): 1
• Digital Multimeter (YOKOGAWA 7561 or equivalent): 1
• Setting tool for adjustment (Refer to “4.2 Connecting the
Setting Tools” in this manual.)
8.2 Calibration Procedure
1. Connect the instruments as shown in gure below.
1011
3 2 1
4
56
789
11
10
8
9
7
5
2
1
3
3
4
GND
ALM2 (NO)
COM
ALM1 (NO)
COM
DMM
DMM
Input
With SINK current
Without SINK current
Alarm-2 output
Alarm-1 output
Power supply
L+
+
N–
–
+
–
voltage and
current
generator
voltage and
current
generator
2. Produce the input signal equivalent to 0% of the input range
from the voltage and current generator to the product.
3. Then, read the input value of Display items, “A01: INPUT1”
using the VJ77 and check that the input value is within the
rated accuracy range.
4. Take the same procedure for the input signal equivalent to 25,
50, 75 and 100% of the input range and check that the input
values are within the rated accuracy range.
For alarm output, check the relay action by the alarm indicator
lamp or resistance of output terminals.
● If it is outside the rated accuracy range, use the VJ77 PC-
based Parameters Setting Tool to make adjustments.
User’s Manual for VJ77 [Document No.: IM 77J01J77-01E]
9. TRANSPORT AND STORAGE CONDITIONS
• Temperature: -25 to 70°C
• Temperature change rate: 20°C per hour or less
• Humidity: 5 to 95%RH (no condensation)
CAUTION
Keep this product in a conductive bag when plugged
out, during transport or storage.