Communication Specifications - Savch SDA2 Series User Manual

7.2 Communication Specifications

Item
Electric I/F
Communication speed
Synchronization method
Communication method
Transmission format
Connection cable
Cable length
(recommended)
Terminator treatment
Character
configuration
Communications
protocol
Communications
mode
Station number
Function code (FC)
Error check method
Message length
Specifications
RS485
38400/19200/9600/115200 [bps]
Asynchronous (UART)
Semi-duplex communication
Master-slave (servo motor drive) = 1:N
(1≦N≦31)
LAN cable (straight) or equivalent
Entire extended length:100 m or less
(up to 38400 bps)
40 m or less (115200 bps)
Length between stations:20 m or less
Master side :100[Ω] recommended
Slave side : Unnecessary
Start bit : 1 bit
Data length : 8 bits
Parity : Even/Odd/None
Stop bit : 1 or 2 bits
Compliant with Modbus RTU protocol
RTU mode
0: Broadcast
1-31: Slave station No.
1(01h): Read out coil data
3(03h): Read out various data
5(05h): Write in single coil data
8(08h): Maintenance (echo back)
15(0Fh): Write in coil data
16(10h): Write in various data
CRC-16 method
Variable length
157
Remarks
Set by parameter (P2.73)
Max. 31 units connected
simultaneously
Set by parameter (P2.93)
The ASCII mode is not
supported.
Set by parameter (P2.72)
Responses other than those in
the left cell are exceptional
responses (improper FC).
Max. 200 bytes