Ohaus GT4100DG Electronic Balances - Manual (Page 42)

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RS232 INTERFACE RS232 INTERFACE RS232 INTERFACE RS232 INTERFACE RS232 INTERFACE
Precision Advanced 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 submin-
iature “D” connector is provided for inter-
facing 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 VDC). 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.
PRINT *
TARE *
1 5VDC (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 con-
tact switches must be used.
Field: T CR LF
Length: 1 1 1
TARE COMMAND
RS232 Commands RS232 Commands RS232 Commands RS232 Commands RS232 Commands
All communication is accomplished us-
ing standard ASCII format. Only the char-
acters shown in the following table are
acknowledged by the balance. Any other
commands, control characters or spaces
are ignored. Commands sent to the
balance must be terminated with a carriage return (CR) or carriage return-line line feed
(CRLF). For example, a tare command should appear as shown in the adjacent
diagram. Data output by the balance is always terminated with a carriage return - line
feed (CRLF).