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.
//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);
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.