Connec-
Signal name Abbrevi-
Signal direction
tor pin #
ation
Input Output
1 Receive data (+) RD (+) Yes
3 Signal ground SG --- ---
5 Send data (+) SD (+) Yes
6 Receive data (--) RD (--) Yes
7 Frame ground FG --- ---
9 Send data (--) SD (--) Yes
Note 1. FG is not connected at the RS-422 Interface Unit end of the cable.
2. Pins #2, #4, and #8 are not used.
Refer to
Appendix B RS-232C/RS-422 Connector Cables
for details on cable
parts and wiring connections.
3-3-3 Precautions
Connect the FG (Pin #7) at one end only to prevent current flowing in the shield-
ing wire, as described below.
Connecting the Link Adaptor and the PT
Connect the shielding wire to FG at the Link Adaptor end of the cable only.
Connecting the Link Adaptors Together
Connect the shielding wire to FG at any one end of the cable.
Turn ON the DIP switch (SW6-10) on the last RS-422 Interface Unit connected
on the cable enable the termination resistance. Refer to
3-2 RS-422 Interface
Unit Switch Settings
for information about setting the DIP switches.
Cable Lengths The cable lengths should not exceed the following limits:
Branch wire: 10 m
Total trunk and branch wires: 500 m
PT PT PT
xxx
xx
Host computer
RS-232C
(upto15m)
B500-AL004
Link Adaptor
Internal termination
resistance ON
Internal termination
resistance OFF
Branch cable
(upto10m)
B500-AL001
Link Adaptor
B500-AL001
Link Adaptor
Branch cable
(upto10m)
Internal termination
resistance OFF
Internal termination
resistance ON
Trunk + branch cable total length up to 500 m.
: Shield wire connected to FG
x : Shield wire not connected to FG
Trunk cable (RS-422)
Branch cable (RS-422) RS-232C
Connecting the Shielding
Wire to FG
Setting the Built-in
Termination Resistance
Section 3-3
To Next Page
Loading...
Need help?
General
