Automation Direct Stellar SR55 Series User Manual

Page 5–6 Stellar
®
SR55 Series Soft Starter User Manual – 1st Ed, Rev F – 09/18/2019
Chapter 5: Communications
modbus serial CommuniCaTions (ConTinued)
WriTe mulTiple regisTers
Description: writing register blocks of holding register type (block R/W limited to 8 registers).
• Function code: 16
Modbus Function 16 Transaction Table
Query Response
Field Hex Byte Field Hex Byte
Slave address 01 Slave address 01
Function 16 Function 16
Address Hi 00 Address Hi 02
Address Lo 0C Address Lo 0C
Force data Hi 00 Force data Hi 00
Force data Lo 09 Force data Lo 09
CRC Lo 48 CRC Lo 49
CRC Hi 0C CRC Hi B4
memory map
SR55 Modbus communication is based on reading or writing equipment parameters from or
to the holding registers. The data addressing is zero offset, such that the parameter Modbus
address corresponds to the register number.
Modbus Address Memory Map
Parameter
Modbus Address
Modbus Data Address
Decimal Hexadecimal
0000 0 0000h
0001 1 0001h
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0128 128 0080h
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message Timing
In the RTU mode there is no specific start or stop byte that marks the beginning or the end
of a message. Indication of when a new message begins or when it ends is achieved by the
absence of data transmission for a minimum period of 3.5 times the transmission time of a
data byte. Thus, in case a message is transmitted after this minimum time has elapsed; the
network elements will assume that the first received character represents the beginning of a
new message.
Message
T
3.5x
T
3.5x
T
interval
T
11 bits
Time

Automation Direct Stellar SR55 Series Specifications

General

Brand	Automation Direct
Model	Stellar SR55 Series
Category	Controller
Language	English