Mitsubishi FR-A800

(N) Operation via communication and its settings
PARAMETERS
559
5
GROUP
N
How to wire RS-485 terminals
• 1 inverter and 1 computer with RS-485 terminals
• Multiple inverters and 1 computer with RS-485 terminals
 Make connection in accordance with the Instruction Manual of the computer to be used with.
Fully check the terminal numbers of the computer since they vary with the model.
 For the inverter farthest from the computer, set the terminating resistor switch to ON (100  side).
NOTE
• For branching, connect the wires as shown below.
Two-wire type connection
• If the computer is 2-wire type, a connection from the inverter can be changed to 2-wire type by passing wires across
reception terminals and transmission terminals of the RS-485 terminals.
NOTE
• A program should be created so that transmission is disabled (receiving state) when the computer is not sending and
reception is disabled (sending state) during sending to prevent the computer from receiving its own data.
RDA
RDB
SDA
SDB
RSA
SG
RSB
CSA
CSB
FG
SG
∗2
-
+
-
+
SDB1 SDA1
RDB1 RDA1
Computer
∗1
∗1
Computer
RDA
RDB
SDA
SDB
RSA
SG
RSB
CSA
CSB
FG
Station 0
SG SG
-
+
-
+
-
+
-
+
Station 1
SG
SG
-
+
+
-
-
+
+
-
Station n
SG
∗2
-
+
SDB1 SDA1
RDB1 RDA1 RDA2 RDB2
SDA2 SDB2
SDB1 SDA1
RDB1 RDA1
SDB1 SDA1
RDB1 RDA1
RDA2 RDB2
SDA2 SDB2
-
+
TXD RXDVCC TXD RXDVCC
To computer send
To computer receive
To computer ground
To receiving terminal
of the next inverter
To sending terminal
of the next inverter
To next inverter
To earth (ground)
terminal
TXD+
TXD-
RXD+
RXD-
SG
SG
InverterComputer
Pass a wire
Transmission
enable
Reception
enable