Connection of RS-485 Interface (V720-CD2D)
Section 4-7
4-19
4-7
Connection of RS-485 Interface (V720-CD2D)
Terminal number
1
2
3
4
Polarity
+
-
+
-
Note Terminals 1 and 3 and terminals 2 and 4 are connected internally in the RS-
485 Controller.
1-to-N Connection
Note After sending a command from the host device, confirm that a response has
been received from the Controller before sending the next command. When
using an RS-232C/485 converter at the host device, do not send commands
until the status has completely changed to clear-to-send status. Also, after
sending all the commands, switch to the receive status. Communications
with the Controller may not be possible if the above points are not observed.
Terminal number
1 2 3 4
Host device
RS-485 Controller 0
With 220-
W
terminating
resistance
Without 220-
W
terminating
resistance
RS-485 Controller 1
Without 220-
W
terminating
resistance
RS-485 Controller 30
With 220-
W
terminating
resistance
Host device
20 ms
V720-CD2D
Command frame
Command frame
Response frame