Communication Protocol - Hyundai n 700 Instruction Manual

N700 Operating Instructions and Parts Manual
(3) Communication order
The flow of the communication protocol between an external control device and an inverter is
shown below in the time diagram.
Frame start :
Frame completion:
Frame 1:
Frame 2:
13.2

Communication protocol

ModBus protocol that applies Query-Response Cycle method is used in the communication.
The communication network is controlled by the master equipment, and it is operated by the
method that the slave equipment reply from the transmission request of the master equipment.
ModBUS communication frame type and form is as follows.
13.2.1 Inverter read frame
It requires 1~8 parameters of Inverter.
(1) External controller transmit frame
Communication
number
Clause
Communication number
Command
Parameter
Parameter number
CRC Hi
CRC Lo
External control
Devices
Inverter
Fig. 13- 3 Communication order
Frame start is recognized by signal line data transmitted.
Frame completion is recognized by no data during correspond 4, 5-
character time.
Transmit from external controller to inverter.
Indication reflects from inverter to external controller.
Frame 2 in inverter displays as the signal that inverter receiving Frame 1 and
recognizes a suitable frame and responds, and don't output actively.
Command
Description
Inverter communication number
Frame type
Parameter
Request parameter
Number
-
-
Table 13- 4 External controller transmit frame
Frame 1
Waiting time
(setting with operator)
Parameter
Parameter
count
Data size
142
13. Communication function
Frame 2
CRC Hi
Specifications
1 byte 1~32
1 byte 0x03
1st byte : Group
2 byte
2nd byte : index
1st byte : 0x00
2 byte
2nd byte : N(0x01~0x08)
1 byte Higher 8bit of 16 bit CRC
1 byte Lower 8bit of 16 bit CRC
CRC Lo