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MODBUS TCP/PN with IM 154-8

Created by: FFGG at: 6/21/2019 1:53 PM (19 Replies)

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6/21/2019 1:53 PM	Rate (0)
FFGG Posts: 20 Rating: (0)	Hi all! I need help with MODBUS TCP/PN. I'm trying to communicate with a device to read its data through modbus. The device uses FC 4 (input register) and the address starting at 40001. Usually it is used for input register addresses starting from 30001, but ok. When I used CAS MODBUS to read the device addresses it read from 30001 and not 40001, as expected. When I made the program I tried several times and nothing works, I have looked at the manual several times and it doesn't work. I am using the IM 154-8 CPU (ET 200 Pro). In the beginning I was giving some errors but I was fixing it, now I see the A006 address error and no matter how much I modify it, it doesn't work. One thing I found strange and noticed today, is that sometimes even if I change the program, when I go online to see the results it gives me the same errors of the previous program that I modified (for example, delete a DB and add a block to another DB). S7: Client I use the block: MODBUSPN Here are attached some prints of the program. I hope they help me, I'm almost going crazy with this program. Thank you in advance. Attachment Screenshot.pdf (385 Downloads)
FFGG Posts: 20 Rating: (0)
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6/21/2019 2:11 PM	Rate (0)
Kaulquappe Posts: 3093 Rating: (323)	Hello, you mixed up the addressing of the data link layer and the application layer. You need start_address=0, data_type=4. Even with the parameterization these values are required. When you try to access a register address which has not been mapped in the parameter DB, error A006 occurs. Please note: parameter changes required an initialiszation of the Modbus FB. As you did not attach online version of the DBs and even the variables in the structures are not displayed, I can't verify which values are used currently. save_STATUS shows the last error that had occurred. You must check count_DONE and count_ERROR as well to know what happened. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)
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6/21/2019 2:30 PM	Rate (0)
FFGG Posts: 20 Rating: (0)	Kaulquappe Hello, you mixed up the addressing of the data link layer and the application layer. You need start_address=0, data_type=4. Even with the parameterization these values are required. When you try to access a register address which has not been mapped in the parameter DB, error A006 occurs. Please note: parameter changes required an initialiszation of the Modbus FB. As you did not attach online version of the DBs and even the variables in the structures are not displayed, I can't verify which values are used currently. save_STATUS shows the last error that had occurred. You must check count_DONE and count_ERROR as well to know what happened. Regards, Kaulquappe Hi Kaulquappe, Thank u very much for your answer. I did what you said, i changed the start_address and got the A080 as an error. As can be seen in the first file of the question, I gave the init in the OB 100 and even so this problem came to me, as shown in the image below. Attachment Screenshot (33).png (344 Downloads)
FFGG Posts: 20 Rating: (0)
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6/21/2019 5:42 PM	Rate (0)
Kaulquappe Posts: 3093 Rating: (323)	Hello, error A080 means the MODBUSPN has not been initialized. Regards, Kaulquappe
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6/21/2019 5:59 PM	Rate (0)
FFGG Posts: 20 Rating: (0)	Kaulquappe Hello, error A080 means the MODBUSPN has not been initialized. Regards, Kaulquappe Hi, I fixed it :) But the problem still continues with the address. I tried putting START_ADDRESS as 3000,30001,4000,40001 and 0 (it seems that this is the correct one) and it didn't work. in DB PARAM, I'm putting data_type: 4 db: my array table start: 0 (I also tried others like 1...) end: 3 and nothing... The pictures show the server address and what I'm getting online. . Regards FFGG Attachment Screenshot 3.pdf (357 Downloads)
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6/21/2019 6:03 PM	Rate (1)
Kaulquappe Posts: 3093 Rating: (323)	Hello, why do you define start_address=0, end_address=3 when you are going to read 10 registers? You can read maximum 3 registers with this parameterization. Regards, Kaulquappe
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6/21/2019 7:31 PM	Rate (0)
FFGG Posts: 20 Rating: (0)	Hi, oh, sorrz..i didn't write all... I wanted to read it: date_type:4 db:1 start: 0 end: 3 date_type: 4 db: 1 start: 8 end: 14
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6/22/2019 6:07 PM	Rate (0)
FFGG Posts: 20 Rating: (0)	Hi! Here it worked but I had a doubt... when I put it: Length = 14 and in PARAM I put it: DATE 1: data_type: 4 start: 0 end: 13 So it works right... but I would like to have the records separated as follows: Length = 14 and in PARAM I put it: DATE 1: data_type: 4 start: 0 end: 3 DATE 2: data_type: 4 start: 8 end: 13 but it doesn't work. What is the correct way to parameterize? Attachment Screenshot 4.pdf (351 Downloads)
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6/22/2019 6:36 PM	Rate (1)
Kaulquappe Posts: 3093 Rating: (323)	Hello, it is not possible to access data in two different DBs with one request. When you want to split the data to different DBs you need two requests. Regards, Kaulquappe
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6/22/2019 8:11 PM	Rate (0)
FFGG Posts: 20 Rating: (0)	Thank you so much for your answer! I imagined it... so i made two requests like you said. So, i used two MODBUS blocks, MODBUS_DB1 and MODBUS_DB2 and did the same procedure i did for DB1 in DB2. I created a connection 2 in PARAM, with the data for that other MODBUS_DB2. But it's giving an error. In MODBUS_DB1 i can read all registers as I put above, i.e. from 0 to 115... but now, i need to read the rest, i.e. from 115 to the next 125 registers that I can read and so on, until I read all the registers. Do any parameterhave to be the same in both blocks? In the images you can see what i did. regards, FFGG Attachment Screenshot 5.pdf (342 Downloads)
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