Scientech S9000 - Manual (Page 14)

14
USING BI-DIRECTIONAL COMMUNICATIONS
Scientech electronic balances, interfaced to a computer via the RS-232 port, can be controlled by a computer program in the same
way an operator would control the balance using a PDA. Any programming language with access to the RS-232 interface can be
used to program this control. The balance expects ASCII character instruction strings and responds with ASCII character data
strings. All characters with an ASCII value less than the space character (decimal 32 of hex 20), are ignored by the balances.
If local control has been enabled (LC on) via RS-232 front panel configuration, RS-232 communication is limited to balance
sending only as all incoming RS-232 command strings are ignored by the balance. To enable bi-directional RS-232
communication, set the local control to off (see RS-232 Front Panel Configuration section).
BI-DIRECTIONAL RS-232 COMMAND SET
The following commands can be sent to the balance in any combination of upper and lower case characters. No action is taken
by the balance until it receives a carriage return indicating the end of the command string. Each command's syntax is described
using this notation; keywords are in upper case; items in [ ] are required; when one item must be chosen from a list, each choice
is enclosed in ( ); CR means the carriage return or enter character; LF means the line feed character; and _ indicates a single
space character. A command string or entry is considered to be a keyword (and/or a numeric string) followed by a carriage
return. The commands are listed by type. Type 1 commands are balance control functions. Type 2 are balance input functions.
Type 3 are balance output functions. Finally, Type 4 are clock/calendar functions. Where a balance response is given, no
attempt has been made to show the actual message formats. You should refer to the section on balance message formats for
detailed information. Numbers stored in the registers are classified by the balance software as being additive, multiplicative, or
unflagged. Additive numbers are used by the balance software in addition and subtraction operations. Multiplicative numbers
are used in multiplication and division operations. Unflagged numbers aren't used in any arithmetic functions. If you try to use
an additive number in a function which requires a multiplicative number the balance responds with the register contents (if
applicable) and a ? and the instruction is ignored.
TYPE 1 COMMANDS (balance control functions)
COMMAND RESPONSE PURPOSE
CLEAR [CR] None Clears the previous command and resets
the balance to normal operating mode.
The Tare register is cleared to zero and
the balance is zeroed.
HI_RANGE[CR] or LO_RANGE[CR]
or AUTO[CR]
None Set the balance range.
GRAMS[CR] or CARATS[CR] or
DWT[CR] or OZT[CR] or OZ[CR] or
A[CR] or LIMITS[CR] or CAL1[CR] or
CAL2[CR]
None Places the balance in the indicated mode
or units. To abort any of the CAL
sequences or the LIMITS modes use
CLEAR[CR].
ZERO[CR] None The balance takes whatever action it
would in response to a push of the front
panel zero switch. Normally tares the
balance.
TARE[CR] None If the balance is in the weighing mode,
this command tares the balance,
otherwise it is ignored.
[decimal number]_HI[CR] None Sets the checkweighing high limit
register (register 88) to the decimal
number entered in the current units.
Register 88 is undefined at every
ON/OFF cycle.
[decimal number]_LO[CR] None Sets the checkweighing low limit
register (register 87) to the decimal
number entered in the current units.
Register 87 is undefined at every
ON/OFF cycle.