Amtech Axpert-Eazy AMT-011-4, Инструкция по эксплуатации

Страница: 191 / 242

Axpert-Eazy AC Variable Frequency Drive
11.3
10
11
CAUTION
Separates the communication cable from the main circuit cable and other power cables.
A shielded twisted pair wire should be used for connecting TB1 and the host computer.
Connect the twisted pair cable's shield to the control earth.
When using several slave units, set JP3 of last unit to ‘LD’ position to connect the terminating
resistors as shown in the Fig. 11-3.
When connecting the TB3 and shielded twisted pair cable, do not solder the wires, which are
exposed after the sheath is peeled off.
If the communication is distorted and not carried out properly because of noise. Connect a
ferrite core to the cable and increase the noise resistance. If required take other precautions
for noise resistance / reduction.
11-4 Communication specifications
Connection method
: RS485, 2-wire type
Transmission distance : Total extension distance less then 300mt (1000ft)
Baud rate : Select from 1200, 2400, 4800, 9600, 19200, 38400bps
Transmission method : Start-stop synchronization, half-duplex communication
Frame configuration : Start - 1 bit
Data - 8 bits
Stop: 1 bit (with parity) or 2 bits (if no parity)
Parity: Select from none, odd or even
Error detection : Sum check, parity, framing
Communication protocol : Modbus-RTU communication
Number of stations : Set between 1 and 247
The default factory settings are shown below.
Parameter Parameter name Unit Value
C401 Baud Rate bps =4: 9600
C402 Station Number =1
C403 Parity =1: No Parity
C404 Response Time Sec =0.01
11-5 Introduction to Modbus
Modbus is a serial, asynchronous protocol. The Modbus protocol does not specify the physical
interface. The typical physical interfaces are RS-232 and RS-485. The Device uses the RS-485
interface.
Modbus is designed for integration with Modicon PLCs or other automation devices, and the services
closely correspond to the PLC architecture. This Device ‘looks like’ a Modicon PLC on the network.
1 Transactions on Modbus Networks
Controllers communicate using a master–slave technique, in which only one device (the master) can
initiate transactions (called ‘queries’). The other devices (the slaves) respond by supplying the