CHIYU BF-850 User Manual

USB/RS-485/RS-422
BF-850 CONVERTER USER MANUAL
I、 FOREWORD
Developing by PC industry, USB interface
replacing many kind of old PC interface step by
step. However, many types of important
equipment still use RS-422/RS-485 interface, in
order to transfer the data between PC and
RS-422/RS-485 interface. That's why we need
to use USB/RS-422/485 converter.
BF-850 is a converter in common use; it
does not need extra power. It also conforms to
the standard of USB, RS-422 and PR-485, and
be able to transfer USB signal to RS-422 or
RS-485 signal. There has no delay automatic
transfer inside, the unique I/O electric
auto-control the direction of data transfer, and
need no handshake signal (like RTS, ETR) to
transfer with full duplex (RS-422) and half duplex
(RS-485).
BF-850 can provide the reliable connection
between point to point and point to multi-points.
In point to multi-points each converter can
connects 32 units of RS-422 or RS-485 interface
equipment. The speed of data transfer is
300~921600 bps and the communication types
are USB to RS-422, USB to RS-485.
II、 Property argument
1. Standard：Conform to the standard of USB
V1.1, EIA RS-485, RS-422.
2. USB signal：VCC、DATA+、DATA-、GND、
FG
3. RS-485 signal：T+、T-、GND
4. RS-422 signal：T+、T-、R+、R-、GND
5. Communication type：Asynchronous
communication, Point to point or point to
multi-points, 2 lines of halt-duplex, 4 lines of
full-duplex.
6. Communication control：use auto-control
technology to transfer the data, automatic
determine and control the direction of data
transfer.
7. Baud Rate：300~921600 bps, automatic
detect the serial port speed.
8. Load ability：In point to multi-points each
converter can connects 32 units of RS-422 or
RS-485 interface equipments.
9. Communication distance：RS-422/RS-485
5000 meter (9600 bps), USB less than 5
meter
10. Type of communication line：Double twist line
or cover line.
11. Communication speed：921600 bps 300 M
38400 bps 2.4 KM
9600 bps 5 KM
12. Dimension：55mm × 36mm × 18mm
13. Operation environment：-25
humidity 5% ~ 95%
14. Support Windows95/98/2000/xp
III、 connection and signal
RS-422/RS-485 export signal
DB9
PINS
1
2
3
4
5
6
7
8
9
IV、 hardware installment and application
Please read the user manual carefully
before install BF-850, connect the USB to PC.
BF-850 use USB/DB-9 connector, and needs no
crossover set to automatic do RS-422 or RS-485
communication type. You can use double twist
line or cover line, so it's very convenience to
combine it. T/R+ T/R- represent the transfer and
receive A+/B-, RXD+/RXD- represent the
receive A+/B-, GND represent the public ground
line, point to point, point to multi-points
half-duplex connect to 2 lines T/R+, T/R-, point
to point, point to multi-points full-duplex connect
to 4 lines T/R+, T/R-, RXD+, RXD-.
~ 70
℃ ℃,
BF-850 provides 4 types of communication
as below：
1. point to point/4 lines full-duplex
2. point to multi-points/4 lines full-duplex
3. point to point/2 lines half-duplex
4. point to multi-points/2 lines full-duplex
RS-422 RS-485
Output
Duplex Half Duplex
T/R+ Transfer(A+) RS-485(A+)
T/R- Transfer(B-) RS-485(B-)
RXD+ Receive(A+) Empty
RXD- Receive(B-) Empty
GND Ground Ground
N/A
N/A
N/A
N/A