Mitsubishi Electric MELSEC FX Series User Manual

FX communication
Wiring 3
3-6
3.3 Using RS-485 Interface
3.3.1 Wiring Selection
The wiring of RS-485 can either be one-pair or two-pair. The wiring method is decided according
to application usage. Please select the wiring method from the table below.
&
…
Recommendation,
'
…
OK,
×…
Cannot use
Note:
*1 When this product is added to the system, please match the wiring to the existing method of
the system.
*2 When using an FX
2N
-485-BD with this wiring method, remember to take account of/or ignore
the “echo” of the commands sent from the FX
2N
programmable controller.
*3 Please use the FX
2N
programmable controller and FX
2N
-485-BD together.
Full-duplex combination cannot be achieved with other configurations.
*4 For wiring parallel link, see section 2.4.
3.3.2 Terminal Resistor
A terminal resistor must be used at both ends of the communication line as described in section
2.3.3 and 2.3.4.
Usage One-pair wiring Two-pair wiring
No protocol
(Use RS instruction) *1
Half-duplex communication
&
*2
'
Full-duplex communication *3
×
'
Dedicated protocol
(Use computer link)*1
It is necessary to set the message
wait time to 70 ms or less.
×
'
It is not necessary to set the
massage wait time to 70 ms or less.
&
*2
'
Use the on-demand function
×
'
Parallel link *4
&
'
N:N network
'
×
Orange Orange Brown
Brown Brown Brown
330
Ω
1/4 W
110
Ω
1/2 W
1 )In the case of two-pair wiring, connect the terminal resistor
(330
Ω
, 1/4W) between terminals SDA and SDB and between
terminals RDA and RDB. Use the resistors offered as
accessories with the product.
2 )In the case of one-pair wiring, connect the terminal resistor
(110
Ω
, 1/2W) between terminals RDA and RDB. Use the
resistors offered as accessories with the product.

Mitsubishi Electric MELSEC FX Series Specifications

General

Brand	Mitsubishi Electric
Model	MELSEC FX Series
Category	Controller
Language	English