DayTronic 3500 Series, Instruction Manual

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B.4
S
ETUP
C
OMMANDS
A SETUP (or "WRITE") COMMAND instructs the 3500 instrument to give a particular
value to a particular setup parameter. It will have the general form
[MNEMONIC] = [value] [CMT]
Examples of setup commands are EMM=3000 [CMT] , FIL=5 [CMT] , ECO=OFF
[CMT] , and SAV=ON [CMT] .
Upon receipt of a setup command, the instrument (in RS-485 mode only) will issue a
response of either "ACKNOWLEDGED" or "NOT ACKNOWLEDGED"—i.e., of either
ACK [EOT] or NAK [EOT]
depending on whether or not the command has been recognized as "valid." As men-
tioned above, a SETUP COMMAND received by the instrument in RS-232 mode will
elicit NO RESPONSE.
Keep in mind that a response of "ACK" does not prove that the "acknowledged" com-
mand has been executed, only that it has been received. Its purpose is to free the
network controller for other communications. To prove execution of a SETUP COM-
MAND, an appropriate INTERROGATION would have to be made.
B.5
I
NTERROGATION
C
OMMANDS
An INTERROGATION (or "READ") COMMAND asks the 3500 instrument for the cur-
rent value of a particular setup parameter. It will have the general form
[MNEMONIC] [CMT]
Examples of interrogation commands are EMM [CMT] , FIL [CMT], ECO [CMT] , and
SAV [CMT] .
Upon receipt of a "valid" interrogation command, the instrument (in either RS-232 or
RS-485 mode) will issue a response of
[value] [EOT]
For example, the response to a command of ECO [CMT] will be either ON [EOT] or
OFF [EOT] , while a command of FIL [CMT] will return the current digital filter con-
stant (0-9).
And as always, if it is an "invalid" command received by the interface in RS-485 mode,
the only response will be
NAK [EOT] .
B.6
I
MPERATIVE
C
OMMANDS
An IMPERATIVE COMMAND does not impart or request information, but rather tells
the 3500 instrument to do something. The general form is like that of an interrogation
command (see above). Upon receipt of an imperative command, the instrument (in
RS-485 mode only) will issue a response of either
ACK [EOT] or NAK [EOT] ,
depending on whether or not the command has been recognized as "valid." Note
that the only strictly IMPERATIVE commands presently in the command set are
RLS
and LNR .
B.2
B
C
OMMAND AND
R
ESPONSE
S
YNTAX
B.4 S
ETUP
C
OMMANDS
B.5 I
NTERROGATION
C
OMMANDS
B.6 I
MPERATIVE
C
OMMANDS