LG MODBUS-RTU User manual

MODBUS-RTU
Option Board for
SV-iS5 Series
Read this manual carefully before using the MODBUS-RTU Option board
and follow the instructions exactly.
After reading this manual, keep it at handy for future reference.
LG Industrial Systems
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Thank you for purchase of LG Modbus-RTU Option Board!
SAFETY PRECAUTIONS
Always follow safety precautions to prevent accidents and potential hazards from occurring.
Safety precautions are classified into “WARNING” and “CAUTION” in this manual.
WARNING
CAUTION
Throughout this manual we use the following two illustrations to make you aware of safety
considerations:
Identifies potential hazards.
Read the message and follow the instructions carefully.
Identifies shock hazards.
Particular attention should be directed because dangerous voltage may be present.
Keep this manual at handy for quick reference.
CAUTION


Do not touch the CMOS components unless the board is grounded.
ESD can cause break down of CMOS components.

Do not change the communication cable with the inverter power is turned on.
Otherwise, there is a danger of connecting error and damage to the board.


Make sure to precisely insert the connector of inverter and option board
Otherwise, there is a danger of connecting error and damage to the board.
Indicates a potentially hazardous situation which, if not avoided, can
result in serious injury or death.
Indicates a potentially hazardous situation which, if not avoided, can
result in minor to moderate injury, or serious damage to the product.



Check the parameter unit when setting the parameters.
Otherwise, there is a danger of connecting error and damage to the board.
modbus-rtu iS5 manual.doc 2

 INTRODUCTION
By using a MODBUS-RTU Option board, SV-iS5 inverter can be connected to a MODBUS-RTU network.
1.1.
When you use the MODBUS-RTU Option Card …
Inverter can be controlled and monitored by the sequence program of the PLC or other master module. The
card provides a terminal block for an RS-485 interface. Up to 32 drives or other Modbus slave devices may
be connected in a multi-drop fashion on the RS-485 Modbus network and may be monitored or controlled by
a single PLC or PC.
1.1.1 Interfacing type of RTU Reference:
- Allows the drive to communicate with any other computers.
- Allows connection of up to 31 drives with multi-drop link system.
- Ensure noise-resistant interface.
Users can use any kind of RS232-485 converters. However a converter that has built-in ‘automatic RTS
control’ is highly recommended. The specifications of converters depend on the manufacturers. Refer to the
converter manual for detailed converter specifications.
1.1.2 Before Installation
Before installation and operation, this manual should be read thoroughly. If not, it can cause personal injury
or damage other equipment.
 SPECIFICATION
2.1.
Performance specification
Items Specifications
Communication method RS485
Transmission form Bus method Multi-drop Link System
Applicable inverter IS5 series drive
Number of drives Maximum 31 drives connectable
Transmission distance Max. 1200m (Less than 700 m recommended)
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Converter RS232-485, Use PC with RS232 card embedded
2.2.
Hardware Specifications
Installation CN2 connector on the inverter control board
Power
Supply
Control B/D From inverter power supply
Comm. B/D From control board (insulated)
modbus-rtu iS5 manual.doc 2

2.3.
Communication Specification
Communication speed 1200 /2400/4800/9600/19200 bps Selectable
Control procedure Asynchronous communication system
Communication system Half duplex system
Character system Binary (8 bit)
Start/Stop bit 1 bit
Error check (CRC16) 2 byte
Parity check None
 PRODUCT DETAIL
3.1.
Layout and detail
Name Description
Connector CN2, Connector to inverter main PCB
Signal
connection
terminal
Communication
signal connection
terminal
P 485 signal - high
N 485 signal – low
G 485 Ground
S Shield
T1
T2
Short T1 and T2 to connect a
termination resistor
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Figure 1. Layout
3.2.
Status LED
CPU LED Indicates normal operation of the board when blinking once per second.
RXD LED Receiving 485 signal
TXD LED Responding to 485 signal
ERR LED
On and Off intermittently Wrong DATA received (Normal
operating)
Blinking with CPU LED at the same
time
DPRAM communication fault
Blinking with CPU LED in an
opposite way
Network Connection TimeOut <I/O-49>
elapsed
 INSTALLATION
1. Connect the option board to the inverter control board using each connector on the board (See the
Figure 1).
modbus-rtu iS5 manual.doc 4

2. Double check the board is firmly installed to the board and then apply the inverter power.
3. When power ON, CPU LED is blinking per second after all LEDs blink one after another.
4. If “CPU LED” is not blinking, turn off the inverter power swiftly (if not, inverter and the board may
get damaged.) and check for the proper installation of the board. If the problem persists, contact
LG distributor.
5. Check ModBus-RTU is displayed in <COM-01>.
6. Set the parameters as below when the above steps are all done.
Parameter code Display Setting Value
< COM-01 > Opt B/D MODBUS displayed automatically
< COM-02 > Opt mode Set the Command controlled via
communication
< I/O- 46 > Inv. number 1~31
(Verify the assigned number is not duplicated)
< I/O- 47 > Baud-rate 9600 bps (Factory default)
< I/O- 48 > Lost command (Note1) User setting
< I/O- 49> TimeOut (Note 1) 0.1 sec (Factory default)
Note 1) it is used for Emergency Stop when communication between inverter and master is not done
properly. It is activated when communication is not done even once for the set time. It means remote
controlling of inverter is not done. Set this value for safety
7. Turn off the inverter power for the connection of the Converter when step 6 is finished.
8. if the inverter is to be placed at the end of the network trunk line, install a jumper at JP1 on the
Modbus card to enable the termination resistor.
 TROUBLE SHOOTING
If communications cannot be established with the drive, there are four LEDs on the Modbus card to aid in
troubleshooting. The CPU LED should blink once per second to indicate that the modbus card is interfacing
with the inverter main PCB properly. The RXD LED should blink each time a properly formed Modbus
message is received that is addressed to the inverter. The RXD LED will not blink when messages are
received that are addressed to other inverters or devices. The TXD LED should blink each time the inverter
responds to a Modbus message. The ERR LED indicates either an invalid request was received or there is
a problem with the Modbus card itself. The ERR LED should never light.
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 CPU LED
State Indicates Corrective measures
Blinking Card is installed properly and working
normally
Off Card is not installed properly Verify that the card is installed
properly
Inverter is not operating normally Verify that the inverter has power
  RXD and TXD LEDs
State Indicates Corrective measures
Blinking Card is functioning normally and receiving
and sending messages
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