Modbus Control - Veikong gpd 515/g5 Startup Manual

5.28

MODBUS CONTROL

The drive can perform serial communication by using a programmable controller (PLC) and

MODBUS protocol. MODBUS is composed of one master PLC and 1 to 31 (maximum)
slave units (GPD 515/G5). In serial communication between the master and slaves, the
master always starts transmission and the slaves respond to it.
The master communicates with one slave at a time. Address numbers are assigned to each
slave in advance, and the master specifies an address to communicate with. The slave
which receives the command from the master executes the function, and then responds to
the master.
A . Communication Specifications
• Interface
• Synchronization
• Transmission parameters
• Protocol
• Maximum number to units
to be connected
B . Sending/Receiving Data
Data that can be sent and received are run/stop commands, frequency reference, fault
reset, drive status, and setting and reading of parameters.
b 1 - 0 1 : Reference Selection
b 1 - 0 2 : Operation Method Selection
Select the run command and frequency reference input method in b 1 - 0 1 and
b 1 - 0 2 . To provide a run command and frequency reference by communication,
set this data to " 2 ". Monitoring of run status, parameter setting/reading, fault
reset and multi-function input command from the PLC are enabled. The multi-function
input command is OR'ed with the command input from control circuit terminals 3-8.
EXAMPLE: b 1 - 0 1 and b 1 - 0 2 settings are " 3 ".
Open : Run by frequency reference from control circuit terminal 13 or 14
Closed : Run by frequency reference and run command from serial
:
:
:
:
:
and run command from control circuit terminal 1 or 2.
communication.
RS-232C (standard); RS-485, RS-422 (option -
requires communication interface card CM085)
Asynchronous
Baud rate — Selectable from 1200, 2400,
4800, 9600 BPS ( H 5 - 0 2 )
Data length — Fixed to 8 bits
Parity — Parity / no parity, even / odd
selectable ( H 5 - 0 3 )
Stop bit — Fixed to 1 bit
MODBUS
31 units (when RS-485 is used)
Factory setting (each): 1
Range (each): 0 to 4
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