Yokogawa VJA7 User Manual

User’s
Manual

IM 77J01A07-01E

Model VJA7
Distributor (Multi-function)

(Isolated Single-output and
Isolated Dual-output Types)

1. CAUTIONARY NOTES FOR SAFE
USE OF THE PRODUCT

For the correct use of this product, read through this manual before
use. The following safety symbol is indicated on the product to en­sure safe use.

CAUTION

If this symbol is indicated on the product, the operator
should refer to the explanation given in the instruction
manual in order to avoid personnel injury or death to either
themselves or other personnel, and/or damage to the instru­ment. The manual describes the special care the operator
should exercise to avoid shock or other dangers that may re­sult in injury or loss of life.

The following symbol marks are used only in this manual.

IMPORTANT

Indicates that operating the hardware or software in a par­ticular manner may damage it or result in a system failure.

NOTE

Draws attention to information that is essential for under­standing the operations and/or features of the product.

4. MOUNTING METHODS

4.1 Wall Mounting

Loosen the main unit-fixing screw of the distributor 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-fixing screw.

Socket

Threaded hole for
fixing the main unit

Main unit

Main
unit-fixing
screw

<Mounting Dimensions>

29.5 or more
22±0.2

2-M4 or 2-ø4.5 or more

Unit: mm

Mounting
screws

2. CHECKING PRODUCT SPECIFI­CATIONS AND THE CONTENTS
OF PACKING

(1) Model Number and Specification Check

Check that the model number and specifications shown on the
nameplate attached on the side of the product are as ordered.

(2) Contents of the Packing

Check that the packing contains the following items:

● VJA7 main unit, 1

● Instruction Manual (IM 77J1A07-01E), 1

● Tag number label, 1

3. GENERAL

This distributor, which belongs to the JUXTA series of signal condi­tioners, receives 4 to 20 mA DC signals from two-wire transmitters
while supplying power to transmitters and converting the received
signal to pairs of isolated current and voltage signals.

• Output-2 signal is selectable from a DC voltage signal, DC

current signal, communication function (RS-485), and alarm
output (two relay contacts).

59±0.3

Fig. 4.1

4.2 DIN Rail Mounting

Locate the distributor so that the DIN rail fits 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

VIEW A

Fig. 4.2

VIEW A (Rear of socket)

DIN rail

Slide lock

Keep this manual in a safe place.

Network Solutions Business Divisiion

2-9-32, Naka-cho Musashino-shi, Tokyo 180-8750 Japan
Phone: [phone] Facsimile: [phone]

IM 77J01A07-01E

1st Edition Nov. 1999

2nd Edition June 2004

2

NOTE

4.3 Mounting Using a Multi-mounting Base

For mounting using a multi-mounting base, see the Instruction
Manual for VJCE (VJ Mounting Base).

4.4 Using Ducts

Wiring ducts should be installed at least 30 mm away from the top
or bottom of the main unit.

4.5

In case of top-and-bottom close mounting

Transmitter should be mounted horizontally with its top and bot­tom slits being vertical. The top and bottom slits should not be
covered.
The area for wiring is required above and below the transmitter
(the area with slant lines).

40 or more40 or more

ALM1

ALM1

ALM1

ALM2

ALM2

29.5 or more

ALM1

ALM1

ALM2

ALM2

(72)

(72)

(29.5)

78 or more

150 or more

ALM2

ALM1

ALM2

• For mounting, use M3 screws and crimp-on terminals with in­sulating sleeves appropriate for the wires used.
Tool of the crimp-on terminals to be used should be appropri­ate for the crimp-on terminals.

• Mount a breaker on the external place.
Mount a switch or 5A circuit breaker on the place near by the
instrument, within operator’s reach. And attach the indication
that it is for disconnecting the instrument.

Input signal

Example of using

COM

2

5

6

-

1

3

44

ALM1

COM

ALM2

a Zener barrier to
configure an
intrinsically safe
system

PS+

+

RS-485

B+

2

A-

5

6

COM

-

COM

-

communication

1

3

4

3 2

56

1011

1
4

789

When internal
power is used

PS+

1

+

-

-

3

COM

Output-2 signal

Analog output

+

2

-

5

Output-1 signal

Analog output

+

7

-

9

When external
power is used

-

+

Alarm output

Fig. 4.3

5. INSTALLATION LOCATION

• For installation, avoid any location where the product may be
subject to vibrations, corrosive gases, or large amounts of
dust, or where the product is exposed to water, oil, solvents,
direct sunlight, radioactive rays, or strong electric or magnetic
fields.

• If there is a possibility that lightening could induce a high
surge voltage on the power and signal lines, provide lighten­ing arresters on the line between the field instrument and in­door instrument in order to protect the product. Install a dedi­cated arrester on the field side and another on the indoor side.

6. EXTERNAL WIRING

WARNING

Turn OFF the power supply and make sure that none of the
cables are not in the hot-line state before carrying out the
wiring to avoid the possibility of electric shock.

Wires are connected to the terminals of the distributor’s socket. M3
screw terminals are provided for the connection of external signals.
Attach a crimp-on lug to each wire for connection to the terminals.

• Recommended cables: A nominal cross-sectional area of 0.5
mm2 or thicker for signal cables, and that of 1.25 mm2 or
thicker for power cables, and shielded twisted-pair cables
(AWG24) for communication wiring cables.

Power Supply

L+

10

N-

11

GND

8

Fig. 6.1

● Keep all sources of noise away from the power and sig-

nal cables. Otherwise, accuracy cannot be assured.

● Provide grounding to a grounding resistance of 100 ⍀.

The length of the grounding cable should be 20 m or
less. Directly connect the lead from the ground terminal
(terminal no. 8) of the distributor to the ground. Do not
carry out daisy-chained inter-ground terminal wiring.

● Direct Current

●

“Overvoltage category (Installation category)” describes
a number which defines a transient overvoltage condi­tion. It implies the regulation for impulse withstand volt­age. “II” applies to electrical equipment which is sup­plied from the fixed installation like distribution board.

●

“Pollution degree” describes the degree to which a solid,
liquid, or gas which deteriorates dielectric strength or
surface resistivity is adhering. “2” applies to normal in­door atmosphere. Normally, only non-conductive pollu­tion occurs. Occasionally, however, temporary conduc­tivity caused by condensation must be expected.

● Rated fuse of 125VDC, 1A is stored. However, opera-

tors can not replace the fuse.

All Rights Reserved. Copyright © 1999, Y okogawa M&C Corporation IM 77J01A07-01E 3rd Edition Mar.31,1997-00

3

IMPORTANT

● If this instrument is used in a manner not sepecified in

this manual, the protection provided by this instrument
may be impaired.

● If the product is operated by a power supply exceeding

the specifications, the product may become extremely
hot and, as a result, damaged. To prevent this, ensure
the following before turning on the power.
(a) The voltage of the supplied power and the input

signal level meet the specifications of the product.

(b) External wires are connected to the correct termi-

nals (refer to Chapter 5).

● Do not operate the product in the presence of flammable

or explosive gases or vapors. To do so is highly danger­ous.

● 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.

7. DESCRIPTION OF FRONT PANEL

AND CONNECTION OF HANDY
TERMINAL

7.1 Front Panel

The communications connector in the front panel is used for setting
up parameters through the Handy Terminal. The alarm-1 and alarm­2 LEDs light up if an alarm occurs (those LEDs are provided only
when the output-2 is specified for alarm output).

7.2 Connecting the Handy Terminal

Connect the modular jack-to-connector adapter to the connection
cable (with 5-pin connector) of the Handy Terminal and then con­nect this adapter to the communications connector of the distribu­tor.

Communications connector

(for connecting the

Handy T erminal)

(lights up if an alarm occurs)

(lights up if an alarm occurs)

* The LEDs are provided only when output-2

is specified for alarm output.

Alarm-1 LED

Alarm-2 LED

Fig. 7.1 Front Panel

F9182EE
Connection cable (optional)

JHT200
Handy T erminal (optional)

Fig. 7.2 Connecting the Handy Terminal

ALM1

ALM2

Communications
connector

E9786WH
Modular jack-to-connector
adapter (optional)

VJ Series

8. SETTING PARAMETERS

Set the parameters using the Handy Terminal. Refer to the list of pa­rameters in this manual and the Instruction Manual for Handy Termi­nal (IM JF81-02E).

8.1 Settings Related to Inputs and Outputs

8.1.1 Square Root Extraction

Select SQR in D11: LINEARIZE.

8.1.2 Low-cut Function

Set this parameter when an input signal is square-root extracted for
use. Set it in D12: LOW CUT numerically.

● Setting range: A range of 0 to 100% of input range

● Setting resolution: 0.1%

Output signal (Y)

Y=X

0

Hysteresis
(Fixed to 0.2%)

8.1.3 Direction of Output Action

Analog output signals can be reversed. To reverse the signal from out­put-1, set D38: OUT1 DR to REVERSE. For output-2, set D39 OUT2
DR to REVERSE. To return the output-1 signal to normal, set D38:
OUT1 DR to DIRECT. For output-2, set D39: OUT2 DR to DIRECT.

8.2 Settings Related to Communication
Function

Set the following parameters when output-2 is specified for com­munication function. For more information on the communication
function, see the Instruction Manual for VJ Series Communication
Function (IM 77J1J11-01E).

8.2.1 Communication Protocol

Set the communication protocol by selecting from among PC­LINK, PC-LINK WITH SUM, MODBUS ASCII, MODBUS
RTU, and LADDER in F01: PROTOCOL.

8.2.2 Communication Address

Set the address number of the distributor numerically in a range of
1 to 99 in F02: ADDRESS.

8.2.3 Baud Rate

Set the baud rate by selecting from among 1200, 2400, 4800, and
9600 bps in F03: BAUD RATE.

8.2.4 Parity

Select and set NONE, EVEN, or ODD in F04: PARITY.

8.2.5 Data Length

Select and set 7 bits or 8 bits in F05: DATA LEN.

8.2.6 Stop Bit

Select and set 1 bit or 2 bits in F06: STOP BIT.

8.3 Settings Related to Alarm Output

Set the following parameters when output-2 is specified for alarm
output.

8.3.1 Alarm Setpoints

Set the alarm setpoints of alarm-1 and alarm-2 in E03: SET
POINT1 and E04: SET POINT2 numerically.

● Setting range: A range of 0 to 100% of input range

● Setting resolution: 0.1%

Input signal (X)

Low-cut point

All Rights Reserved. Copyright © 1999, Y okogawa M&C Corporation IM 77J01A07-01E 3rd Edition Mar.31,1997-00

4

8.3.2 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 (low­limit alarm) and set each in E05: ALM1 ACTION (direction of
alarm-1 action) or E06: ALM2 ACTION (direction of alarm-2 ac­tion).

● To activate alarm status when input signal ⱖ alarm setpoint,

select HIGH ALM.

● To activate alarm status when input signal ⱕ alarm setpoint,

select LOW ALM.

8.3.3 Hysteresis

Set 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: A range of 0 to 100% of input range

● Setting resolution: 0.1%

9. DESCRIPTION OF ALARM ACTIONS

This chapter describes examples of alarm actions under the following conditions.

metI

noitcamralafonoitceriDNOITCA1MLA:50Emralatimil-hgiHNOITCA2MLA:60Emralatimil-woL

gnittesmralA1TNIOPTES:10E%082TNIOPTES:20E%51

siseretsyH1SISERETSYH:70E%012SISERETSYH:80E%5

yaledNOmralA1YALEDNO:11E.ces12YALEDFFO:21E.ces3

yaledFFOmralA1YALEDFFO:31E.ces22YALEDFFO:41E.ces4

[%]

100

mralafonoitpircseD

Alarm conditions established

[1] [2]

Alarm conditions established

High-limit alarm ON

Normal conditions established

Normal conditions established

snoitca

1-mralA2-mralA

retemaraPtniopteSretemaraPtniopteS

.lamronotsnrutersutatseht,sdnoces2

[1]: Alarm status does not continue for more than 1 second after the

High-limit alarm OFF

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.

8.3.4 Alarm ON Delay and Alarm OFF Delay

Set 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 a delay time from the establishment of
alarm condition to alarm output; an alarm OFF delay is a delay
time from the establishment of return-to-normal condition to out­put.

● Setting range: 0 to 999 seconds

● Setting resolution: 1 second (Note that about 0.2 second will

be added to set time to prevent erroneous operation.)
For example, when an alarm ON delay is set to 1 second, alarm
output is generated if alarm status continues for more than 1 sec­ond 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 more than 2 seconds after the input
value has returned to normal from the alarm status.

8.3.5 Direction of Relay Action

Set the direction of relay energizing in alarm-1 normal condition
and alarm-2 normal condition by selecting from among NRM DE­ENERGIZED (de-energized under normal condition) and NRM
ENERGIZED (energized under normal condition) in E15: RL1
ACTION and E16: RL2 ACTION and set them.

tupniehterehwnoitidnocehtfisdnuosmralaehT

seunitnocmralatimil-hgihfoeromro%08sieulav

,sdnuosmralaehtretfA.dnoces1nahteromrof
nahtsselsieulavtupnierehwnoitidnocehtnehw
nahteromrofseunitnocmralatimil-hgihehtfo%07

tupniehterehwnoitidnocehtfisdnuosmralaehT

seunitnocmralatimil-wolfosselro%51sieulav

,sdnuosmralaehtretfA.sdnoces3nahteromrof
nahteromsieulavtupnierehwnoitidnocehtnehw
nahteromrofseunitnocmralatimil-wolehtfo%02

.lamronotsnrutersutatseht,sdnoces4

80

60

40

20
15

Alarm-1 action
Alarm-2 action

1 sec.

Alarm-2 hysteresis (5%)

0

Normal

Alarm-1 ON delay

2 sec.

Alarm-1 OFF delay

Alarm-2 setpoint (15%)

Alarm

Normal Alarm Normal

Alarm-1 setpoint (80%)

Alarm-1 hysteresis (10%)

Alarm conditions

established

[3] [4]

Alarm-2 ON delay

Alarm conditions

established

3 sec. 4 sec.

Low-limit alarm ON

established

Normal

Normal conditions

Alarm-2 OFF delay

Normal conditions

established

Elapsed time

Low-limit alarm OFF

All Rights Reserved. Copyright © 1999, Y okogawa M&C Corporation IM 77J01A07-01E

1 sec.

10.LIST OF PARAMETERS

1011

3 2

1
4

56

789

Input signal

11

10

8

L+

N-

GND

Power Supply

9

7

Analog output

Output-1 signal

4

3

+

-

4 to 20 mA DC input

Voltmeter

R

R: For current output using 250 Ω

precision resistor

Voltage and

current

generator

+

-

5

2

Analog output

Output-2 signal

Voltmeter

R

R: For current output using 250 Ω

precision resistor

+

-

.oNmetIyalpsiDskrameR.oNmetIyalpsiDskrameR

10ledoMLEDOM

20.ongaTONGAT
30tluserkcehc-fleSKHCFLES

A1yalpsiD1YALPSIDB2yalpsiD2YALPSID

10AeulavtupnI1TUPNI10B1eulavtupnI1TUPNI
50A1eulavtuptuO1TUPTUO50B1eulavtuptuO1TUPTUO
60A2eulavtuptuO2TUPTUO60B2eulavtuptuO2TUPTUO
70Asutats1-mralASUTATS1MLA06Btluserkcehc-fleSKHCFLES
80Asutats2-mralASUTATS2MLA
71AsutatSSUTATS1*
81A.on.veRONVER
02A.veruneMVERUNEM
06Atluserkcehc-fleSKHCFLES

D)O/I(gnitteS)O/I(TESE)tuptuomrala(gnitteS)MLA(TES

10D1.ongaT1.ONGAT10Egnittes1-mralA1TNIOPTES
20D2.ongaT2.ONGAT20Egnittes2-mralA2TNIOPTES
30D1tnemmoC1TNEMMOC30Egnittes1-mralA1TNIOPTES
40D2tnemmoC2TNEMMOC40Egnittes2-mralA2TNIOPTES
11DeziraeniLEZIRAENIL50Enoitca1-mralafonoitceriDNOITCA1MLA
21DtucwoLTUCWOL60Enoitca2-mralafonoitceriDNOITCA2MLA
83Dnoitca1-tuptuofonoitceriDRD1TUO90Esiseretsyh1-mralA1SISERETSYH
93Dnoitca2-tuptuofonoitceriDRD2TUO01Esiseretsyh2-mralA2SISERETSYH
06Dtluserkcehc-fleSKHCFLES11EgnittesyaledNO1-mralA1YALEDNO

.deificepssituptuo

PtnemtsujdA1TSUJDAQtseTTSET

20P1tupnifotnemtsujdaoreZ1JDAOREZ10QCJRfoFFO/NOCJR
30P1tupnifotnemtsujdanapS1JDANAPS20Q1tuptuodecroFTSET1TUO
21P1tuptuofotnemtsujda%0%01TUO30Q2tuptuodecroFTSET2TUO
31P1tuptuofotnemtsujda%001%0011TUO40Q)1mrala(tuptuodecroFTSET1MLA
41P2tuptuofotnemtsujda%0%02TUO50Q)2mrala(tuptuodecroFTSET2MLA
51P2tuptuofotnemtsujda%001%0012TUO06Qtluserkcehc-fleSKHCFLES
06Ptluserkcehc-fleSKHCFLES

smetiyalpsiD

1*yrotsiheesotlennosrepecivresrofdeyalpsidsisutatSehT

.sdrocer

smetignitteS

21EgnittesyaledNO2-mralA2YALEDNO
31EgnittesyaledFFO1-mralA1YALEDFFO
41EgnittesyaledFFO2-mralA2YALEDFFO
51Enoitcayaler1-mralafonoitceriDNOITCA1LR
61Enoitcayaler2-mralafonoitceriDNOITCA2LR
06Etluserkcehc-fleSKHCFLES

F)noitacinummoc(gnitteS)MOC(TES

dnocestahwnognidnepeddeyalpsidtonsmetieraerehT

smetignitsujdA smetitseT

10FlocotorpnoitacinummoCLOCOTORP
20FsserddASSERDDA
30FetarduaBETARDUAB
40FytiraPYTIRAP
50FhtgnelataDNELATAD
60FtibpotSTIBPOTS
06Ftluserkcehc-fleSKHCFLES

5

11.MAINTENANCE

If the output signal is out of the rated accuracy range, adjust the

output signal level using the Handy Terminal (JHT200).
The product starts running immediately when the power is turned on;
however, it needs 10 to 15 minutes of warm-up before it meets the
specified performance.
For cleaning the instrument, use a soft and dry cloth.

11.1 Calibration Apparatus

● A voltage and current generator (Yokogawa 7651 or the

equivalent)

● A voltmeter (Yokogawa 7562 or the equivalent)

● A precision resistor of 250 ⍀ ± 0.01%, 1 W (for current out-

put)

11.2 Calibration Procedure

Connect the instruments as shown in Fig. 10.1. First adjust the out­put-1 signal and then the output-2 signal.
Produce input signals equivalent to 0, 25, 50, 75, and 100% of the
input span (or those equivalent to 0, 6.25, 25, 56.25, and 100% of
the input span if square root extraction is set) from the voltage and
current generator to the distributor. Then, check that the
distributor’s output signal shows voltages corresponding to 0, 25,
50, 75, and 100% of the input span within the rated accuracy range.

All Rights Reserved. Copyright © 1999, Y okogawa M&C Corporation IM 77J01A07-01E

Fig. 11.1