Advanced Energy Paramount MF 2 kW, Руководство пользователя

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specifies the purpose of the message packet. If the message originates with the
Paramount MF 2 kW unit, the value specifies the command to which it is responding.
AE BUS OPTIONAL LENGTH BYTE
This field supplements the header field and exists only when the length bits (bits 0, 1,
and 2) in the header field contain a value of 7 (07h). If the number of data bytes in
the data field is ≤ 6, then the three length bits in the header field are sufficient to
represent this amount, 0 to 6 (00h to 06h). Since the data field contains up to 255
bytes of information, the optional length byte is required when the data field is larger
than six bytes.
When the data field is larger than six bytes, the length bits in the header (bits 0, 1,
and 2) equals 7 (07h) and the optional length byte contains a 1-byte value, from 7 to
255 (07h to ffh), representing the number of data bytes in the data field.
AE BUS DATA BYTES
The data field contains 0 to 255 bytes of binary data. This field contains command-
related data or a command status response (CSR). Since some commands do not
require data, sometimes the data field is not present.
If the value specified in the length bits (bits 0, 1, and 2) of the header field is 0 to 6,
the Paramount MF 2 kW unit expects 0 to 6 data bytes. However, if the value in the
header field is 7 (07h), the Paramount MF 2 kW unit looks for the optional length
byte after the command field and reads this value to calculate the data byte count.
Unless otherwise specified for individual commands, AE Bus protocol is little
endian, which means that all values greater than 1 byte are sent in little endian order.
For example, a command with 7 data bytes that included one 8-bit value, one 16-bit
value, and one 32-bit value, would be sent as shown in
Table 4
‑
8 .
Table 4‑8. AE Bus byte structure
Value to Send Byte Configuration
8-bit value = 15 Byte 1 = 0x0F
16-bit value = 23450 Bytes 2 and 3 = 0x9A 0x5B
32-bit value = 147679 Bytes 4 to 7 = 0xDF 0x40 0x02 0x00
AE BUS CHECKSUM BYTE
This 1-byte field is the last byte in the packet. The value of this byte depends upon
the number of bytes in each of the preceding fields. The transmitting unit determines
this value by accumulating the exclusive-or (XOR) of all bytes of the packet up to,
but not including, the checksum value. The receiving unit accumulates the XOR of
all bytes of the packet, including the checksum. If the result is zero, the unit has
received the packet intact.
Advanced Energy
®
Paramount
®
MF 2 kW Generator
57020114-00E Communication Controls 4‑16