TPG CA-203A, Руководство по эксплуатации

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Warranty Card
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diverse character intervals under network baud rate,which is easiest implemented (as
shown in Figure T1-T2-T3-T4) . The first field transmitted is the device address. The
allowable characters for transmitting are hexadecimal 0 ... 9, A ... F. The networked
devices continuously monitor network bus, including during the silent intervals. When
the first field (the address field) is received, each device decodes it to find out if it is
sent to their own. Following the last transmitted character, a silent interval of at least 3.5
characters marks the end of the message. A new message can begin after this silent
interval. The entire message frame must be transmitted as a continuous stream. If a
silent interval of more than 1.5 characters occurs before completion of the frame, the
receiving device will flushes the incomplete message and assumes that the next byte
will be the address field of a new message. Similarly, if a new message begins earlier
than the interval of 3.5 characters following a previous message, the receiving device
will consider it as a continuation of the previous message. This will result in an error,
because the value in the final CRC field is not right.
RTU frame format:
Frame header START T1-T2-T3-T4 (transmission time of 3.5-byte)
Slave address field
ADDR
Address: 0 to 247 (decimal) (0 is the broadcast address)
Functional field CMD
03H: read slave parameters;
06H: write slave parameters
Data field
DATA (N-1) …
DATA (0) 2*N bytes of data, the part is the main contents of
communications, but also the data exchange core during
communicating.
CRC CHK low-order
CRC CHK high-order
Detection value: CRC checksum (16BIT)
Frame tail END T1-T2-T3-T4 (transmission time of 3.5-byte)
(2) In ASCII mode, each byte format is as follows:
In ASCII mode, the frame header is ":" ("0x3A"), the default frame tail is "CRLF"
("0x0D" "0x0A") . In ASCII mode, in addition to header and trailer, the rest of all data
bytes are sent in ASCII code, firstly sent the high 4 bytes, and then send the low 4 bytes.
In ASCII mode, the length of data is eight bytes. For 'A' to 'F', the uppercase ASCII code
is adopted. At this point the data adopts LRC parity, the parity covers slave's address
and data. The sum of parity is equal to the complement of the character sum (discard the
carry bit) of all data to be checked.
ASCII frame standard structure:
START ‘:’ (0x3A)
Address Hi
Address Lo
Address :8-bit address consists of 2 ASCII codes
Function Hi Function code :8-bit address consists of 2 ASCII codes
Warranty Card
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Function Lo
DATA (N-1)
…
DATA (0)
Data Content: nx8-bit data consists of 2n combinations of ASCII
code
n <= 16, maximum 32 ASCII codes
LRC CHK Hi
LRC CHK Lo
LRC check code: 8-bit check code consists of 2 ASCII codes
END Hi Terminator: END Hi = CR (0x0D), END Lo = LF (0x0A)
CMD (Command) and DATA (Data word description) command code: 03H, read N
words (Word) (up to 16 words can be read), such as: the starting address 0001 of
inverter with slave address 01, which continuously read 2 consecutive messages of RTU
master command .
START T1-T2-T3-T4
ADDR 01H
CMD 03H
Start address high-order F0H
Start address low-order 01H
Data number high-order 00H
Data number low-order 02H
CRC CHK low-order
CRC CHK high-order
CRC check value
END T1-T2-T3-T4
RTU slave responding information
F9.05 is set to 0:
START T1-T2-T3-T4
ADDR 01H
CMD 03H
Byte number low-order 00H
Byte number high-order 04H
Data address 0001H high-order 13H
Data address 0001H low-order 88H
Data address 0002H high-order 00H
Data address 0002H low-order 00H
CRC CHK low-order
CRC CHK high-order
CRC check value
END T1-T2-T3-T4