Ohaus AP250E ANALYTICAL Plus Electronic Balances - Manual (Page 11)

11
PRINT *
TARE *
1 5 V dc (5 mA max.)
2 Data Out (TXD)
3 Data In (RXD)
4* Tare (External signal)
5 Clear To Send (CTS)
6 Data Terminal Ready (DTR)
7 Ground
8 Request To Send (RTS)
9* Print (External signal)
* External PRINT and/or TARE
switches may be installed as
shown in the diagram. Momentary
contact switches must be used.
Field: T CR LF
Length: 1 1 1
TARE COMMAND
RS232 INTERFACE RS232 INTERFACE RS232 INTERFACE RS232 INTERFACE RS232 INTERFACE
ANALYTICAL Plus balances are equipped with a bi-directional RS232 compatible
interface for communication with printers and computers. When the balance is
connected directly to a printer, displayed data can be output at any time by simply
pressing PRINT, or by using the Auto Print feature.
Connecting the balance to a computer enables you to operate the balance from the
computer, as well as receive data such as displayed weight, weighing mode, stability
status, etc.
The following sections describe the hardware and software provided with the balance.
Hardware Hardware Hardware Hardware Hardware
On the rear of the balance, a 9-pin sub-
miniature “D” connector is provided for
interfacing to other devices. The pinout
and pin connections are shown in the
adjacent illustration.
The balance will not output any data un-
less pin 5 (CTS) is held in an ON state (+3
to +15 V dc). Interfaces not utilizing the
CTS handshake may tie pin 5 to pin 6 to
defeat it.
Output Formats Output Formats Output Formats Output Formats Output Formats
Data output can be initiated in one of three
ways: 1) By pressing PRINT; 2) Using the
Auto Print feature; 3) Sending a print com-
mand (“P”) from a computer.
The output format is illustrated in the
RS232 command table which follows.
RS232 Commands RS232 Commands RS232 Commands RS232 Commands RS232 Commands
All communication is accomplished using
standard ASCII format. Only the charac-
ters shown in the following table are ac-
knowledged by the balance. Any other
commands, control characters or spaces
are ignored. Commands sent to the bal-
ance must be terminated with a carriage
return (CR) or carriage return-line line
feed (CRLF). For example, a tare com-
mand should appear as shown in the
adjacent diagram. Data output by the bal-
ance is always terminated with a carriage
return - line feed (CRLF).
INSTALLATION