Advanced Energy HFV 8000, User Manual

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5705211-C Communication Interfaces 4-13
HFV 8000 Generator
The host computer must finish one transaction with the HFV generator before it
initiates another, either with the same unit or any other unit.
Note: The HFV generator sends data through pin 2 ( TXD.D ). This pin must be
connected to the receive pin ( RXD.D ) on the host computer’s PC serial
connector. The receive pin is normally pin 2 for a standard, 9-pin PC serial port
and normally pin 3 for a standard, 25-pin PC serial port.
AE Bus Protocol
The AE Bus protocol uses pure binary data (nothing is coded in ASCII) and is
designed to facilitate direct communications between a host computer and the HFV
generator.
The AE Bus message packet combines a set quantity of bits and bytes in such a way
that groups of information can be sent over communications lines at one time. Five
types of information (fields) make up communications message packets (see
Figure 4-
9 ):
• Header (address and the length of Data field)
• Command Number (the commands are listed in Table 4-7 on page 4-20 )
• Optional Length byte
• Data
• Checksum
Figure 4-9 shows the organization of these fields in the AE Bus message packet. The
subsequent paragraphs describe each field in detail.
Figure 4-9. Graphic representation of a message packet