
User’s 
Manual
Model VJH1 
Isolator 
(Isolated Single-output and 
Isolated Dual-output Types)
IM 77J01H01-01E
Please read through this User’s Manual before use for correct handling. 
Please keep this User’s Manual for future reference.
IM 77J01H01-01E
1st Edition Jul. 2003 (MC)
2nd Edition June 2004 (YK)
Network Solutions Business Divisiion
2-9-32, Naka-cho Musashino-shi, Tokyo 180-8750 Japan 
Phone: +81-422-52-7179 Facsimile: +81-422-52-6793
1. CAUTIONARY NOTES FOR SAFE USE OF THE PRODUCT
This User’s Manual should be carefully read before installing and operating the product. The following symbol is used on the product and in 
this manual to ensure safe use.
This symbol is displayed on the product when it is 
necessary to refer to the User’s Manual for information on 
personnel and instrument safety. This symbol is displayed 
in the User’s Manual to indicate precautions for avoiding 
danger to the operator, such as an electric shock.
The following symbols are used only in this manual.
4.1 Wall Mounting
Loosen the main unit-fixing screw of the product and pull out the main 
unit from the socket. Fix the socket on the wall with screws. Next, insert the main unit into the socket and fasten the main unit with the main 
unit-fixing screw.
Output-1
Zero-adjustment volume
Span-adjustment volume
Output-2
Zero-adjustment volume
Span-adjustment volume
IMPORTANT
Indicates that operating the hardware or software in a 
particular manner may cause damage or result in a system 
failure.
<Mounting Dimensions>
NOTE
Draws attention to essential information for understanding 
the operations and/or functions of the product.
Main unit
29.5 or more 
22±0.2
59±0.3
Mounting
screws
Main 
unit-fixing 
screw
2-M4 or 2-ø4.5 or more
Socket
Threaded hole for 
fixing the main unit
Unit: mm
2. 
CHECKING PRODUCT SPECIFICATIONS AND PACKAGED ITEMS
(1) Checking the Model and Product Specifications
Check that the model and specifications indicated on the nameplate 
attached to the side face of the main unit are as ordered.
4.2 DIN Rail Mounting
Insert a DIN rail into the upper part of the DIN rail groove on the rear of 
the socket, and then slide the slide lock at the lower part of the socket 
upwards until the socket is fixed into position as shown below.
(2) Packaged Items
Check that the packing carton contains the following items:
● VJH1: 1
● Tag number label: 1 sheet
● Shunt resistor (for current input): 1
● User’s Manual (this manual: IM 77J01H01-01E): 1 copy
DIN rail
3. GENERAL
This plug-in type isolator converts DC current or DC voltage signals into 
isolated DC current or DC voltage signals.
4. MOUNTING METHOD
NOTE
Insert/pull out the main unit into/from the socket vertically 
to the face of socket. Otherwise the terminals are bent and 
it may cause a bad contact.
4.3 Mounting Using a Multi-mounting Base
When using a multi-mounting base, see the User’s Manual for VJCE 
(VJCE Mounting Base).
4.4 Using a Duct
When using a wiring duct, install the duct at leaset 30 mm away from 
the top and bottom faces of the main unit.
Fit into here
DIN rail
Push
(Rear of the socket)
DIN rail
Slide lock

5. INSTALLATION LOCATIONS
● Avoid the following environments for installation locations: 
Areas with vibration, corrosive gases, dust, water, oil, solvents, direct sunlight, radiation, a strong electric field, and/or a strong 
magnetic field
● 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 this unit 
and a field-installed device.
6. EXTERNAL WIRING
WARNING
To avoid the risk of an electric shock, turn off the power 
supply and use a tester or similar device to ensure that no 
power is supplied to a cable to be connected, before carring 
out wiring work.
Wiring should be connected to the terminals on the socket of the product. The terminals for external connections are of M3 screws. Use 
crimp-on terminal lugs for connections to the terminals.
● Recommended cables: A nominal cross-sectional area of 0.5 mm 
or thicker for signal cables, and that of 1.25 mm2 or thicker for 
power cables.
External receiving resistor
(Shunt resistor) 
for current input
3 2
1
56
4
789
1011
Power Supply
1110 8
GND
N–
L+
Input signal
+
1
Ri
–
3
Ri
: External receiving resistor for
   current input (See the table below.)
Output-2
+
2
–
5
Output-1
+
7
–
9
7. MAINTENANCE
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.
7.1 Calibration Apparatus
● A DC voltage/current standard (Yokogawa 7651 or the equivalent)
● A digital multimater (Yokogawa 7561 or the equivalent)
● A precision resistor of 250  ± 0.01%, 1 W
7.2 Calibration Procedure
(1) Connect the instruments as shown below. First adjust the output-1
signal and then the output-2 signal.
(2) Use the DC voltage/current standard and apply input signals
equivalent to 0, 25, 50, 75, and 100% of the input span to the 
product. Check to see the corresponding output voltages are 0, 
25, 50, 75, and 100% respectively and within the specified accuracy rating. “R” is used for current output.
● If the output signals are out of the accuracy rating range, adjust 
the output signal level using the zero and span adjustment volumes on front face of the product.
External receiving resistor
2
(Shunt resistor) 
for current input
Input
DC voltge/ 
current 
standard
Ri: External receiving resistor 
   for current input 
   (See chapter 6.)
1
Ri
3
3 2
1
56
4
789
1011
Power supply
1110 8
N
L
GND
Output-2
2
Digital
Ro
multimater
5
Output-1
7
Digital
Ro
multimater
9
Ro: 250  precision resistor 
   for current output
<External Receiving Resistor (Shunt Resistor) for Current Input>
Input ragne 
 10 to 50 mA DC 
  4 to 20 mA DC 
  0 to 20 mA DC
 0 to 16 mA DC
Resistance
Part No. Input ragne
100 
E9786WD
250 
E9786WE
 2 to 10 mA DC 
0 to 10 mA DC 
 1 to 5 mA DC 
 0 to 1 mA DC
Resistance
500 
1 k
IMPORTANT
●
The power line and input/output signal lines should be 
installed away from noise-generating sources. Other 
wise accuracy cannot be guaranteed.
●
The grounding resistance must be 100 Ω (JIS Class D 
grounding). 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 daisychained inter-ground terminal wiring.
●
Use of the product ignoring the specifications may 
cause overheating or damage. Before turning on the 
power, ensure the following: 
(a) Power supply voltage and input signal value applied
to the product should meet the required 
specifications.
(b) The external wiring to the terminals and wiring to
ground are as specifications.
●
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.
Part No.
E9786WF
E9786WG
2
IM 77J01H01-01E 2nd Edition June 01,2004-00