Modbus RS485 FX3U

[Bisayok]

Excuse me guys, i use PLC FX3U-14MT  from china. So, i have 2 flow sensor and i want to read flow sensor using RS485 modbus communication. But i dont know how to ladder it. i've tried using IVRD and ADPRW but still cannot read my sensor. Please help me, here my ladder before.

[Nugro]

 

Did you use FX3U-485ADP-MB ? Maybe you can share your sensor here, and what you want to read

You can try this. It may work.

Parameter. you can change transmission speed according to device (slave)

Edited Saturday at 09:59 PM by Nugro

[Parky]

It's a clone so probably does not support the MB adapter those chinese clones generally have a built in 485 port & the PLC Parameters cannot be changed & downloaded.

Here is a video of how to do it if it is an clone.

How to Configure FX3U PLC as a Modbus Slave and how to read write the data from PLC through Modbus - YouTube

https://www.youtube.com/watch?v=cPuX4ga1Ods

 

 

[Bisayok]

So i use gas flow sensor from siargo MF5712. in that sensor i can setting the address of the slave.

19 hours ago, Nugro said:

 

Did you use FX3U-485ADP-MB ? Maybe you can share your sensor here, and what you want to read

You can try this. It may work.

Parameter. you can change transmission speed according to device (slave)

 

[Bisayok]

6 hours ago, Parky said:

It's a clone so probably does not support the MB adapter those chinese clones generally have a built in 485 port & the PLC Parameters cannot be changed & downloaded.

Here is a video of how to do it if it is an clone.

How to Configure FX3U PLC as a Modbus Slave and how to read write the data from PLC through Modbus - YouTube

https://www.youtube.com/watch?v=cPuX4ga1Ods

 

 

so its cannot use ADPRW instruction?

[Parky]

Need more information for example is it definitely a clone with the built in 485 port ?.

i.e. just a board with a simple see through case or does it look exactly like the real unit.

If it is the clone then probably does not support the ADPRW instruction there are many youtube vids on many of the different clone versions, although these are so called FX3U are probably slightly modified FX2N or FX3U old versions of firmware, most do not support altering the PLC Parameters or expansion cards & seem to be set at 19200 or 38400 baud for GXDeveloper, the real FX's can be forced to any baud rate by GXDeveloper on the fly but to answer your question if this has the built in 485 then probably does not support it.