 The HA7E is a RS232 to 1-Wire interface in a very small
ABS enclosure designed to provide an ASCII command set for RS232 serial hosts
that need to accommodate Dallas Semiconductor iButton and 1-Wire devices.
The HA7E relieves the host of the burden of generating the time–critical 1–Wire
communication waveforms while supporting all 1-Wire devices with simple ASCII commands
that can be easily generated. The HA7E does all the hard work of interfacing 1-Wire
networks.
Small size and very low power consumption as well automatic power-up and power-down
features allow the HA7E to operate in low power and battery operated applications
with no need for power control signals from the host device. The only interface
signal required is the RS23 level TX, RX, RTS and DTR. . When a serial ASCII
command is sent the HA7E will wake-up, process the command, send the response and
power down. The 1-Wire bus can be left in a powered up or a powered down state
while the HA7E is powered down. While in power down mode the HA7E has
a very low quiescent current requirement.
The HA7E can perform Search and Family search functions making it easy to acquire
the unique 64 bit serial numbers of all connected devices. Many sensor devices require
that extra power be delivered during periods of data conversions (DS1920 and DS1820
temperature sensors for example). The HA7E automatically provides the extra current
these devices require with a built in smart strong-pull-up. Dallas Semiconductor
iButtons which store data in TMEX Touch Memory File format can be read or written
with simple ASCII commands. The HA7E will automatically generate and check the CRC16
error checks from Touch Memory File records. The HA7E supports analog, digital,
and temperature 1-Wire devices and all Dallas Semiconductor iButtons.
Features
- ASCII command support for all 1-Wire devices.
- Powered by RS232 handshake lines.
- Automatic power up and power down.
- Automatically provides smart strong-pull-up.
- 1000 feet, 100 devices per CAT-5 twisted net.
- Search, Family Search and Conditional Search.
- ESD Protection more than 27kV (IEC801-2 Reference Model.) on the 1-Wire
bus.
- Block mode commands support all 1-Wire device functions.
- Automatic CRC16 for TMEX files.
- ABS enclosure.
- Low Cost.
Specifications
- Communications: 9600, N, 8, 1
- Supply Voltage: 6-16.5 Volts
- Supply Current (during command): 2-4 mA
- Strong Pullup Short Circuit current: 35 mA
- Supply Current (quiescent): 60-400 MicroAmp
- 1-Wire Devices: 100 devices
- CAT-5 Cable length: 1000 feet
iButton and 1-Wire are registered trademarks of Dallas Semiconductor Corporation.
TMEX is a trademark of Dallas Semiconductor Corporation.
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