Mitsubishi Electric FX-485ADP User Manual page 6

2.2 Examples of one-pair wiring (for RS-485 circuit)
(1) When connecting one computer and one PC
485PC-IF
Signal name
SDA
SDB
RDA
R *1
RDB
LINK SG
Grounding
resistance of
100 or less
(2) Computer and PCs in 1 : n connection ( n has a maximum value of 16 ).
The terminal lagout shown is diagrammatic only. As for 485ADP, see chapter 1, and as for 485PC-IF, and
computer link unit for A series PC, see the individual manuals.
Computer 485PC-IF
SD SD
R
RD RD
*1 R is the terminating resistance. Connect the terminating resistance (110 ) between terminals
RDA and RDB . For details see section 2.3.
*2 Connect terminal FG to earth terminal
or less. However, as for the computer link unit of the A series PC, see the manual of the computer
link unit.
*3 The 24V DC power requirement can be taker from the service power supply of the PC.
Cable connection and signal direction
FX base unit
485ADP
Station
No. 0
SDA
SDB
*
1
RDA
RDB
LINK
LINK
SG
DC24V
485ADP
Station
No. 1
SDA SDA
SDB SDB
RDA RDA
RDB RDB
LINK
SG SG
* *
2
FG FG
of the PC main body grounded with resistance of 100
485ADP
Application
Signal name
RDA Reception data
R *1
Reception data
RDB
SDA Transmission data
SDB Transmission data
LINK SG Signal ground
FG
Frame ground
*2
24V
Power supply terminal
*3
24G Power supply terminal
*3
485ADP
Station
No. 15
SDA
SDB
RDA
RDB
LINK
SG
*
2 2
FG
*1
R