Mitsubishi FX5CPU Apps With RS485[Non-Protocol Communication]

Hi, this topic is a basic instruction and wrote some memo in here while i using Mistsubishi FX5U application of RS485 interface control.Why i write this? because in the manual there is not so many details and example about these information;(…

Non-Protocol Communication

Firstly, What is non-protocol communication?
It is a communication method that used to exchange the data between printer,bar code reader..Etc.

For More Information:
Serial Communication by Wiki

system configuration

Because the CPU that i am using here is FX5U, only GXWorks3 is available.
*Be honestly, GXWorks3 is not a good item…. ;)!Shut Up!!

Wiring.

In RS485 there are One-pair wiring and Two pair wiring, and in this application, the devices is only support one-pair wiring.
*the wiring will effect the Termination resistor setting and communication setting inside the GXWorks project, I will explain these stuffs on the below.

Termination resistor

For One-Pair wiring, please push theTermination resistor selector switch to 110 ohm.
For Two-Pair wiring, please push theTermination resistor selector switch to 330 ohm.

Communication Setting in GXWorks3

Navigation Window ->Parameter -> FX5UCPU -> Module Parameter ->485 Serial Port
I will not explain so much on what is Data Length,Parity Bit…Something like this, please check inside the Wiki or MR Google ;).

Programming-

OK! Now is the time to explain how to make a PLC program that can use non-protocol communication to exchange the data between other devices.

Step1- Check the Instruction

Instruction “RS2” is the main in here.

Reference to the Manual:

This instruction sends and receives data in non-protocol communication using the communication board or communication
adapter connected to the CPU module or using the built-in RS-485 port to the CPU module.

I hope that i will have time to write the program in Ladder and ST both 😉 i wish..

Step2:Useful Devices

In the Manual there are so many devices that can get the error code of communications, settings, ABCDEFG.. But in here I will Only show the devices that is the main heart to run the program.

SM8561-
The Flag that using to send the data, you must use a pulse signal to turn it on, and
SM8562:The Flag will auto reset while the sending action is finished.

SM8562-
The Flag that will turn on while all the data is received.It is auto turn on and you must reset it in program.

SD8562-
The System DM that save how many data is received. It is a very useful DM that to make a simple check to make sure all the data that you want is received, then do your own data operation.(move,+-*/,etc..)

Step3:Coding

Now is the time to start programming it!
Here is a basic Example that coding by ST Language with some comment.

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//RS485 non-protocol communication Example
//SM8561 Send Active Flag
//SM8562 Receive Finish Flag
//SD8561 Data Receive Count
//SM8500 Communication ERROR Flag

//While the PLC Sent ‘ID05SET'(ASCII Code) to RS485 Interface devices.
//The Interface will return ‘ID05SETOK’ in the OK Condition.

D400:D:= H35304449;
D402:D:= H544553;
D450:=K7;
D470:=K9;

OUT(SM8500,M0); //Communication Error Flag

If SM8562 then
If SD8561=k9 Then // All Data Received
//Do some data operation With D500;
FMOV(TRUE,D500,K10,D600)//Just move all data to other DM
END_IF;
END_IF;

OUT_T(NOT T2,T2,K2);
SET(T2,SM8561);
RST(SM8562,SM8562);

//Always Exchange Data Between Other Devices.
//DM Start to send from D400
//Send 7 data D400-D404
//Receive 9 data (Byte)
//At Channel 1
//Data Received from devices staring at D500

RS2(TRUE,D400,D450,D470,K1,D500);
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Thanks and please write the comment if you have any things that would like to discussed;)!
And i will write another one for the RS485-MODBUS communication,CCLink and Ethernet with FX5U.

Bye~~..
Omg, I forgot something..
Here is the link to download the operation manual of FX5U.
Please check it to get more information.

FX5UManual