1 of 2
091100
DS9097U
Universal 1-Wire
COM Port Adapter
FEATURES
True-ground interface to an RS232 COM Port
for reading and writing 1-Wire devices
Works with bipolar as well as unipolar logic
signals
Compatible to COM ports of ()5V to ()12V
(DB-9 version only) or ()6V to ()12V
(DB-25 version)
Supports reading and writing at regular and
Overdrive speeds
Provides strong pull-up to 5V for Tempera-
ture-, Crypto- and EEPROM 1-Wire devices
Programs 1-Wire EPROM devices (DB-25
version with external 12V power supply only)
Communicates at data rates of 9.6 (default),
19.2, 57.6 and 115.2 kbits/s
Standard DB-9 or DB-25 female connector
and 6-lead RJ-11 connector for easy attach-
ment of standard 1-Wire cables and probes
Includes DS2502 identification chip
(DS9097U-009 only)
PIN ASSIGNMENT
DB-25: TXD (2), RXD (3), DTR (20), RTS (4),
PC-Ground (7); all other pins not connected
DB-9: TXD (3), RXD (2), DTR (4), RTS (7),
PC-Ground (5); all other pins not connected
NOTE:
The external supply for the DS9097U-E25 must
provide well regulated 12V @ 10 mA minimum,
center = GND, outer ring = V+ (Newark
Electronics Stock No. 84F2081, Allied
Electronics Stock No. 928-9895, Stancor Model
STA-300R, or equivalent)
ORDERING INFORMATION
DS9097U-009
DB-9, with DS2502 ID chip
DS9097U-S09
DB-9, no ID chip
DS9097U-E25
DB-25, with EPROM write
PACKAGE OUTLINE
DB-09 version
SIDE VIEW
REAR VIEW
RJ-11 pin 1
DB-25 version
RJ-11 pin 1
SIDE VIEW
REAR VIEW
+ contact
- contact
2.1mm
power jack
SCHEMATIC
(for illustration)
DB-9 version
6
4
RTS
DTR
RXD
TXD
GND
RS232
COM Port
5V
Reg.
DS
2480B
1
7
8
5
2
RJ-11
1-W
GND
6
5
4
3
2
1
ID
Chip
DS9097U-009
only
DB-25 version
6
4
RTS
DTR
RXD
TXD
GND
RS232
COM Port
5V
Reg.
DS
2480B
1
7
8
5
2
RJ-11
1-W
GND
6
5
4
3
2
1
Power Jack
9V
www.dalsemi.com
DS9097U
2 of 2
091100
DESCRIPTION
The DS9097U is a sophisticated RS232 to 1-Wire Adapter, which performs RS232 level conversion and
actively generates the 1-Wire communication signals. Together with an adequate TMEX software driver
it enables an IBM-compatible PC to directly communicate with any 1-Wire device connected to the
adapter's RJ-11 port. The DB-9 version reads and writes any non-EPROM 1-Wire device. To write to
EPROM devices the DB-25 version with external power supply is required.
All DS9097U adapters are based on the DS2480B Serial 1-Wire Line Driver chip and therefore are not a
plug-in replacement for the DS9097 or DS9097E. The RXD/TXD Polarity Select input of the
DS2480B is tied to Vdd (non-inverting). Free software drivers can be downloaded from
http://www.ibutton.com/software/tmex/index.html.
The DS9097U communicates with 1-Wire devices at regular speed as well as Overdrive speed. The serial
port must support a data transmission rate of 9600 bits/s. Under software control, the adapter can be set
up for RS232 data rates of 19200, 57600 and 115200 bits per second. The two higher rates are rec-
ommended for communication at Overdrive speed with Overdrive capable devices. Since the DS9097U
operates in a byte mode, every data byte received from the RS232 port generates eight time slots on the
1-Wire line. At 19200 bits/s data rate the DS9097U-E25 is already faster than the DS9097 (E) at 115200
bits/s.
Note that there are some COM ports that use signal levels of less than (
) 5V. The DB-9 versions of this
adapter will not work with such ports. The DS9097U-E25 adapter, however, will function in most cases if
external power is supplied. Without EPROM programming the external power may be anywhere in the
range of 6 to 9V. For EPROM programming the voltage must be at 12V in any case. Before using an
externally powered DS9097U-E25 with a COM port of less than (
) 5V check whether the COM port will
not be damaged by 5V on its RXD input.
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