Azbil F4Q, User Manual

Page: 11 / 76

2-1
Chapter 2. Wiring
2 - 1 RS-485 Connection
A sample connection is shown below.
Master station
DA
FG
FG
Terminating resistor
Terminating resistor
Relay terminal block
Slave station
(this device, etc.)
Slave station
(this device, etc.)
Slave station
(this device, etc.)
Slave station
(this device, etc.)
Relay terminal block
Shielding
Shielding
DB
SG
DA
DB
SG
DA
DB
SG
DA
DB
SG
DA
DB
SG
FG
• Attach terminating resistors (150 Ω ±5 %, ½ W min.) to both ends of the
transmission line.
• A relay terminal block is required because this device uses a connector.
• The cable to the relay terminal block from this device must be as short as
possible.
• The frame ground must be connected to only one end of the shielded cable, not
to both ends.
Handling Precautions
•
Be sure to connect the signal ground (SG) terminals to each other. Otherwise,
communication may be unreliable.