VFD and PLC serial communication (RS485/Modbus-RTU) 

sir plz expalin when write data ( set Frequency) Run/Stop commands send to D1304. But When you Read Data you put #0004 to the D1304 as A Read Length, I Cant Understand that, PlZ Expalin it, From SriLanka

@@samwicks4885 #0004 to D1302

Sorry，I don’t know.

If the data transmission is normal, then OK.

Sorry, I have not used the NX1P2 series PLC, they may be similar in settings, but the DM fixed allocation word may be different. I suggest you download the NX1P2 unit operation manual on the OMRON official website to see how to use serial communication in the manual.

1. You need to know the frequency storage address of the VFD, as well as the start-stop address; 2. Prepare two MOV instructions, high-speed instruction & low-speed instruction, start instruction and stop instruction; 3. Send high-speed commands and low-speed commands to the VFD frequency storage area respectively through Modbus protocol; 4. Transmit the start command to the VFD via the Modbus protocol, and command the VFD to start (or stop) immediately; 5. You need to establish real-time communication between PLC and VFD (you can read VFD operating conditions such as frequency or current parameters at regular intervals); 6. When an error occurs in real-time communication, a special storage area bit will be set to 1. This data can be used to control the PLC output IO. 7. Use PLC's output terminal IO to control VFD by hardware when communication error occurs. , At least one of my ideas above. When you have a full understanding of Modbus, you will have many ways to achieve your goals. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dpTmeJODdVU.html

@@ATOcom thanks so much for the response!

2:15 to 2:32 for setting, no need ladder.

The lights are always on.

Add the VFD address program in the PLC.

Check whether the communication parameters are correct, such as whether the inverter address is correct, the baud rate or the hardware connection is correct.

The received data cannot be used directly, and it needs to be converted or combined in hex.

@@ATOcom u1-03 hex adress 42 = 66 dec +1 add 67 I write but the data sounds different

@@ahmetozar7937 Check whether the data in the adjacent memory is related.

@@ATOcomoutput current = 00FBH = 251 Developed when he wrote his address. Thank you for your interest

In the user's manual.

@@ATOcom thank you I'll.check it out

You can go to the official website of the PLC you own to download the manual and find it.

This is the length of the read data, executed in the 03 command.

@@ATOcom Can you explain to me different between D1304 and D1302?

@@anhoangduc4626 D1302 stores the data length of the 03 command. D1304 stores the length of the read data (read the length of the data returned from the VFD).

@@ATOcom what do you mean "D1302 stores the data length of the 03 command" we cant undersatnd "03 command"

@@ATOcom i think you mean "03command" for the Read command code.. but sir you put #0004 to the D1302 also,, it also transmission data length, you says D1304 as a Read data length, what is the different of D1302 and D1304? please explain this for all of the guys who commented below...

Set 4 different VFD station number addresses (P3.10) to: 001, 002, 003, 004, and call different VFD programs corresponding to the unused station number addresses.

@@ATOcom Thanks

Sorry, I have not recorded my program. You can find it completely in the video.

ATO VFD frequency setting address is 2001H, you can use 06 command write 2001H to D1303 ,write frequency to D1304....

@@ATOcom THANKU

OK

Sorry, this program has been lost, but you can find it completely from the video.

ATO VFD frequency setting address is 2001H, you can use 06 command write 2001H to D1303 ,write frequency to D1304....

@@ATOcom PLZ explain this correctly,,,Above you corected the VFD fequency storge address as #2102 to D1303. At there You says #2001 to D1303. And YoU say Write Fequency to D1304. But in the video You put Commands( #0001Run, #0007Stop) to D1304. Please sir Describe this Correctly. God bless you!

sir please give me a correct answr for this.....i beg your pardon for desturbing

ATO VFD frequency setting address is 2001H, you can use 06 command write 2001H to D1303 ,write frequency to D1304....

Thank u

@@ATOcom Write fequency to D1304? It cant be understand, In the video when write data you Put command adresses to d1304 such as RUn,Stop(#0001/#0007)

@@samwicks4885 You need to understand the Modbus RTU communication format, which is easy for you to understand. The principle is that by writing different data to the special storage area of the VFD, the VFD can execute different commands. This video will help you, ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Yst9iJ6xfgc.html

Sorry, I don't have WA. You can ask here.

Sir you have tutorial modbus tcp plc omron?

​@@jimiiskandar4843 Sorry, we don't have a tutorial on modbus TCP at present, but we will do it in the future.

Ok sir.