Tf830 Remote/Local Operation; Tf830 Remote Commands - TTI TF830-RS232 Manual De Instrucciones

TF830 REMOTE/LOCAL OPERATION

At power-on the instrument will be in the local state with the REMOTE
LED off. In this state all front panel operations are possible. When the
instrument is addressed to listen and a command is sent the remote state
will be entered and the REMOTE LED will be turned on. In this state the
front panel is locked out and remote commands only will be processed.
The instrument may be returned to the local state by holding down the
RESET key and pressing the RANGE key; however, the effect of this
action will remain only until the instrument is addressed again or receives
another character from the ARC interface, when the remote state will
once again be entered.

TF830 REMOTE COMMANDS

Because of the use of a four bit microcontroller the command parser
uses only the lower four bits of the characters sent over the serial
interface. This means that many combinations of character will be
accepted for each command. Only one combination is given below and
this is the one that is most obvious. For example. the RESET command
is R<pmt> but 2<pmt> or b<pmt> will also work. The hex value given
along with each command is the four bit code which is passed to the
parser. Control characters are significant in all 8 bits and do not have
alternatives. Responses from the TF830 are correctly formatted as 8 bit
ASCII character codes, and are terminated with CR/LF.
Note that each command is completely executed before the next com-
mand is started.
SPACE character (0h) No Operation.
The command is ignored.
R (2h) Reset.
Performs the same operation as pressing the front panel RESET key
under the same conditions.
S? (3h Fh) Status Query.
Reads and returns the instrument status. The response is sent immedi-
ately, if in non-addressable mode, or when addressed to talk, if in
addressable mode. The response is:-
xy<rmt>
Where x and y are numeric digits expressed in ASCII format. The first
digit is the status byte and is a bit significant value in the range 0 to 7.
The meaning of each bit is as follows:-
bit 0 External standard connected.
bit 1 An error has occurred. The error number follows.
bit 2 Triggered. A continuously updated bit indicating that an input
signal has been detected. At frequencies below 20Hz this bit
may toggle and may therefore not give a reliable indication of
the triggered condition.
The second byte contains the error number of the last error that occurred.
The value is cleared to zero after each status query. Error numbers are
as follows:-
0 No error has occurred since the last status query.
1 A command syntax error - one or more commands ignored.
2 Terminator missing - command ignored.
TC (4h 3h) Trigger level to centre position.
TN (4h Eh) Trigger level to negative pulse position.
TP (4h 0h) Trigger level to positive pulse position.
This group of commands are used to set the trigger level to one of the
three preset positions. Centre is equivalent to the trigger level control in
the mid position. Negative pulse and positive pulse are equivalent to the
extreme anti-clockwise and clockwise positions, respectively, of the
trigger level control. For more information on trigger level see the section
on Trigger Level Control. The trigger level is set irrespective of the
position of the front panel control. When remote state is first entered the
trigger level is set to centre. When remote state is cleared the trigger
level reverts to the setting of the front panel control.
E? (5h Fh) Every Result Query.
N? (Eh Fh) Next Result Query.
? (Fh) Current Result Query.
This group of commands return the results of measurements to the
controller. The response is sent immediately, if in non-addressable
mode, or when addressed to talk, if in addressable mode. The ? form
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