Connecting Rs-485; 9-2-1One-To-One Connection; 9-2-2Multiple Connection - Unipulse F320 Operation Manual

9.RS-485 INTERFACE (Communication protocol; Modbus-RTU)

9-2. Connecting RS-485

9-2-1. One-to-one Connection
PLC/programmable
display, etc.
A
B
(Master)
• For connection, use twisted pair cables. (The noise margin will rise.) However,
• On the F320 side, mount the attached terminating resistance.
•
9-2-2. Multiple Connection
A
B
Terminating resistance
73
Terminating
resistance
Terminating
resistance
(accessory)
A A
B B
a parallel two-core cable is good enough for short-distance connection.
The terminal SG (the terminal B6) is a grand terminal used on the circuit for protecting
the circuit.When the main body of F320 and the device connected to F320
grounded by D type ground, there is usually no need to use the terminal SG.
However, confirm the specifications of the devise connected before connecting
the terminal SG, when it is necessary to connect it according to the situation of
the site.
Request
On some master devices, A and B may be indicated reversely. If
communications are unsuccessful, interchange A and B.
F320 F320
A B
A
Twisted pair cables
F320
A
B
(Slave)
F320
B A B
* Logic
• Mark state (OFF)
V -V <-0.2V
A B
• Space state (ON)
V -V >0.2V
A B
V : Voltage of terminal A
A
V : Voltage of terminal B
B
are
F320
A B
Terminating
resistance