Sanken S06-4A005-B Instruction Manual page 183

⑴ Message transmission and receive timings between inverter and computer
The transmission and receive timings of RTU message are as follows:
Response mode——————————————————————————————————
Broadcast mode—————————————————————————————————
T1: Data receive complete time
The maximum time for judging 1-frame data complete by message receive cycle is the time needed to transmit 3.5-bit data with
current baud rate. Therefore, the response signal must be after the time of T1.
T2: Communication response time (F4004)
By changing the communication time, the response interval sent by inverter can also be changed.
The response mode is a normal or error response sent by inverter to the command from the PC.
No response is sent in broadcast mode.
〈Communication timeout function〉
In ModBus communication, the setting of function code F4101: ModBus communication timeout can be used to set the
response timeout during communication.
When exceeding the time period set by F4101, the inverter will act according to the setting of function code F4102: ModBus
communication timeout actions.
F4102=0 Status keeping
F4102=1 Alarm stop (GAL3 alarm)
Message format
⑵
The message format is as follows. The RTU format is consisted with data in hexadecimal.
IN: Address (inverter number)
The 1byte length for IN is selectable from 0-254, 0 refers to broadcast mode (batch operation).
OP: Operation code (command code)
Used as a command code
The 1byte length for OP is defined as the following table from 0-255. Blanks with shading are used by OP.
DT: Data
DT contains all information (register, data and etc.)
SUM: CRC (checksum)
SUM is the 2byte length of CRC check mode.
The followings are examples of messages (computer → inverter, inverter → computer (normal & abnormal response)).
1) Message from computer to inverter (RTU)
PC—inverter
Command signal
T1
PC—inverter
Command signal
Variable length
OP
Not used
0～2
3 (03H) Register reading
Not used
4～5
6 (06H) Single register writing
Not used
7～15
16 (10H) Continuous register writing (max. one data)
Not used
17～127
Saved as exceptional response
128～255
inverter—PC
Response signal
T2
inverter—PC
No response
Description
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