Agilent Technologies TwisTorr 305 FS User Manual page 86

8 Technical Information
RS 232/RS 485 communication description
Table 4
DATA TYPE
Logic (L)
Numeric (N)
Alphanumeric (A)


The addressed SLAVE will respond with an ANSWER whose structure depends
from the MESSAGE type.
When the MESSAGE is a reading command, the SLAVE will respond
transmitting a string with the same structure of the MESSAGE.
Using the RS 485 interface, the message structure remains identical to the one
NOTE
used for the RS 232 interface, the only difference being that the value assigned
to the ADDRESS <ADDR>
The controller can answers with the following response types:
Table 5
Type
Logic
Numeric
Alphanumeric
ACK
86/102
FIELD LENGTH
1
6
10
<ETX> (End of transmission) = 0x03
<CRC> = XOR of all characters subsequent to <STX> and including the
<ETX> terminator. The value is hexadecimal coded and indicated by two
ASCII character.
Response types
Length
1 byte
6 bytes
10 bytes
1 byte
TwisTorr 305 FS onboard Controller User Manual / 87-901-060-01
VALID CHARACTERS
'0' = off
'1' = on
'-', '.', '0' . . . '9' right
justified with '0'
from blank to '_' (ASCII)
Value Description
- After a read instruction of a logic
window
- After a read instruction of a numeric
window
- After a read instruction of an
alphanumeric window
(0x6) The command execution has been
successfully completed