Agilent Technologies TwisTorr 84 FS PCB, Руководство пользователя

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17 Technical Information
Data Exchange Protocols

For host messages this field is present only in case of writing
containing logic, numeric or alphanumeric data types according
to the following table.

For controller messages this field is always present containing
the required data (logic, numeric or alphanumeric) in case of
reading or the relevant protocol answer in case of writing
acknowledge or protocol errors.
Tab. 6
Length Characters Permitted
Logic (L) 1 ‘0’= off
‘1’= on
Numeric (N) 6 ‘-‘, ‘.’, ‘0’ . . . ‘9’ right
justified with ‘0’
Alphanumeric (A) 10 from blank to ‘_’ (ASCII)

<ETX>
(End of transmission) = one character containing 0x03

<CRC>
= two characters containing XOR of all characters
subsequent to
<STX>
and including the
<ETX>
terminator. The value is hexadecimal
coded and indicated by two ASCII character.
Only the addressed SLAVE will respond.
NOTE
Using the RS-485 interface, the message structure remains identical to the one
used for the RS-232 interface, the only difference being that the value assigned
to the ADDRESS <ADDR>
192/210 TwisTorr 84 FS PCB 24 Vdc Controller User Manual / 87-901-039-01 (B)