Mitsubishi Electric FR-A800, Instruction Manual

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Parameters (N) Operation via communication and its settings
FR-A800 5 - 605
●
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 Ω side).
Two-wire type connection
If the computer is 2-wire type, a connection from the inverter can be changed to 2-wire type by pass-
ing wires across reception terminals and transmission terminals of the RS-485 terminals.
I002731E
Fig. 5-306: Connection to several inverter
NOTE For branching, connect the wires as shown below.
I002733E
Fig. 5-307: 2-wire type connection
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.
∗1
RDA
RDB
SDA
SDB
RSA
SG
RSB
CSA
CSB
FG
SG SG
-
+ - +
-
+ - +
SG SG
-
+
+
- -
+
+
-
SG
∗2
-
+
SDB1 SDA1
RDB1 RDA1 RDA2 RDB2
SDA2 SDB2 SDB1 SDA1 RDB1 RDA1
SDB1 SDA1 RDB1 RDA1
RDA2 RDB2 SDA2 SDB2
-
+
Computer
Station 0
Station 1 Station n
TXD RXD VCC TXD RXD VCC
To computer ground
To computer receive
To computer send
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
Transmission
enable
Reception
enable
Computer
Inverter
Pass a wire