EN-38
9.4.2
RS232 (DB9)
Diagram
USB Interface
The Ohaus USB Interface is a unique solution to the problem of connecting a balance to a computer using a
Universal Serial Bus (USB). USB devices are categorized into classes such as disk drives, digital cameras, printers,
etc. Balances do not have a commonly used class so the Ohaus USB interface uses a generic interface based on
the RS232 serial standard.
Data sent from the balance to a computer is in USB format. The USB data is directed to a virtual port. This port
then appears as an RS232 port to the application program.
When sending a command from a computer to the balance, the application program sends a command to the
virtual port as if it were an RS232 port. The computer then directs the command from the virtual port to the
computers USB connector where the balance is connected. The port receives the USB signal and reacts to the
command.
System Requirements
PC running Windows 98
Windows 8
(32-bit) or Windows 10
®
Available USB port (Type A, 4-pin, female)
Type
Interface type
Max. cable length
Signal level
Connector
Operating mode
Transmission mode
Transmission code
Baud rates
Bits / parity
Stop bits
Handshake
End-of-line
, Windows 98SE
, Windows ME
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®
.
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Description
Voltage interface conforming to EIA
RS-232C/DIN 66020 (CCITT
V24/V.28)
15 m
Output:
+5 V ... +15 V (RL = 3 – 7kΩ)
-5 V ... -15 V (RL = 3 - 7 kΩ)
Input:
+3 V ... +25 V
-3 V ... -25 V
Sub-D, 9-pole, female
Full duplex
Bit-serial, asynchronous
ASCII
1200, 2400, 4800, 9600, 19200,
38400 (firmware selectable)
7-bit/even, 7-bit/odd, 7-bit/none,
8-bit/none (firmware selectable)
Stop bit 1, 2
None, XON/XOFF, RTS/CTS
(selectable)
Not selectable
, Windows 2000
, Windows XP
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®
PXP Series Balance
, Windows 7
or
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