Windows Protocol - Agilent Technologies TwisTorr 305-IC X3513-64000 User Manual

8 Technical Information

Windows Protocol

Windows Protocol

The Windows Protocol is a MASTER/SLAVE type where:
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The communication is performed in the following way:
1. the host (MASTER) send a MESSAGE + CRC to the controller (SLAVE);
2. the controller answer with an ANSWER + CRC to the host.
The MESSAGE is a string with the following format:
<STX>+<ADDR>+<WIN>+<COM>+<DATA>+<ETX>+<CRC>
where:
When a data is indicated between two quotes ('...') it means that the indicated
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data is the corresponding ASCII character.
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Host = MASTER
Controller = SLAVE
<STX> (Start of transmission) = 0x02
<ADDR> (Unit address) = 0x80 (for RS 232)
<ADDR> (Unit address) = 0x80 + device number (0 to 31)
(for RS 485)
<WIN> (Window) = a string of 3 numeric character indicating the window number
(from '000' to '999'); for the meaning of each window see the relevant paragraph.
<COM> (Command) = 0x30 to read the window, 0x31 to write into the window
<DATA> = an alphanumeric ASCII string with the data to be written into the
window. In case of a reading command this field is not present. The field length
varies according to the data type as shown in the following table:
TwisTorr 305-IC User Manual / 87-901-058-01