Distributor of Digi International: Excellent Integrated System Limited
Datasheet of XC09-038PKC-R - MODEM RF 900MHZ RS232/485
Contact us: [email protected] Website: www.integrated-circuit.com
9XCite™
RS
‐
232/485
RF
Modem
–
Product
Manual
v2.1
[2007.01.04]
©
2007
MaxStream,
Inc.
11
Figure
2
‐
14. XCite
RF
Modem
in
an
RS
‐
422
environment
RS-485/422 Connection Guidelines
The RS-485/422 protocol provides a solution for wired communications that can tolerate high
noise and push signals over long cable lengths. RS-485/422 signals can communicate as far as
4000 feet (1200 m). RS-232 signals are suitable for cable distances up to 100 feet (30.5 m).
RS-485 offers multi-drop capability in which up to 32 nodes can be connected. The RS-422 proto-
col is used for point-to-point communications.
Suggestions for integrating the XCite RF Modem with the RS-485/422 protocol:
Figure
2
‐
15. Male
DB
‐
9
to
RJ
‐
45
Adapter
(yellow)
Figure
2
‐
16. Female
DB
‐
9
to
RJ
‐
45
Adapter
(green)
An XCite RS-232/485 RF Modem ‘Accessories Kit’ is available that includes connectors that facilitate
RS-485/422 and other serial communications.
1.
When using Ethernet twisted pair cabling: Select wires so that T+ and T- are connected to
each wire in a twisted pair. Likewise, select wires so that R+ and R- are connected to a
twisted pair. (For example, tie the green and white/green wires to T+ and T-.)
2.
For straight-through Ethernet cable (not cross-over cable) - The following wiring pattern
works well: Pin3 to T+, Pin4 to R+, Pin5 to R-, Pin6 to T-
3.
Note that the connecting cable only requires 4 wires (even though there are 8 wires).
4.
When using phone cabling (RJ-11) - Pin2 in the cable maps to Pin3 on opposite end of
cable and Pin1 maps to Pin4 respectively.
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