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UNIT input on MODBUSCP(FB108) block related to MODBUS TCP/IP

Created by: a.z.r at: 6/26/2014 6:40 AM (11 Replies)

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6/26/2014 6:40 AM	Rate (0)
a.z.r Bronze Member Joined: 6/8/2013 Last visit: 10/1/2024 Posts: 188 Rating: (1)	HI ALL CAN SOMEBODY GIVE ME COMPLETE INFORMATION ABOUT UNIT INPUT IN MODBUSCP BLOCK ? I READ MANUAL OF THIS BLOCK BUT I DIDN'T UNDERSTAND WHAT DOES THIS INPUT? THANKS ALOT

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6/26/2014 11:05 AM	Rate (1)
Kaulquappe Posts: 3093 Rating: (323)	Hello a.z.r., UNIT is the parameter which was the slave address with serial communication. It is only used with different values when communicating with a serial/TCP gateway. The standard values for UNIT are 1 or 255 - depending on the communication partner. If a distinct UNIT is required, it is mentioned in the manual of the 3rd party device. FB108 parameterized as server responds to all UNIT numbers received. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)
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This contribution was helpful to 1 thankful Users Joel Rock

6/27/2014 1:47 PM	Rate (0)
a.z.r Bronze Member Joined: 6/8/2013 Last visit: 10/1/2024 Posts: 188 Rating: (1)	thank you Mr.kaulquappe

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3/2/2015 3:54 PM	Rate (0)
Joel Rock Regular Member Joined: 12/29/2014 Last visit: 11/12/2024 Posts: 16 Rating: (0)	Kaulquappe Hello a.z.r., UNIT is the parameter which was the slave address with serial communication. It is only used with different values when communicating with a serial/TCP gateway. The standard values for UNIT are 1 or 255 - depending on the communication partner. If a distinct UNIT is required, it is mentioned in the manual of the 3rd party device. FB108 parameterized as server responds to all UNIT numbers received. Regards, Kaulquappe Hello Kaulquappe , but as the MODBUSCP addresses where the information is stored locally for each slave? Example: If you have a server with ID 1 and you want to save data as a slave with addresses 20 and 21 using one MODBUSCP. This is what I currently have for the slave 20, but where the data would be saved for slave 21 MODBUSCP_PARAMETER ID1_ID WORD W # 16 # 1 ID1_laddr WORD W # 16 # 110 ID1_server_client BOOL TRUE ID1_single_write BOOL FALSE ID1_reserved BYTE B # 16 # 0 ID1_data_type_1 BYTE B # 16 # 3 // Holding Register ID1_db_1 WORD W # 16 # 3C // DB60 ID1_start_1 WORD W # 16 # 0 // 0 (40001) ID1_end_1 WORD W # 16 # 55 // 84 (40085) Thank You

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3/2/2015 4:55 PM	Rate (1)
Kaulquappe Posts: 3093 Rating: (323)	Hello Joel, there is only a data source/destination per IP address. When you connect a gateway and address serveral servers via one IP address you must copy the data from/to a different DB. Copy the data before starting a write request or after finishing a read request. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)	Last edited by: Kaulquappe at: 3/2/2015 4:56:49 PM
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This contribution was helpful to 1 thankful Users Joel Rock

3/2/2015 8:28 PM	Rate (0)
Joel Rock Regular Member Joined: 12/29/2014 Last visit: 11/12/2024 Posts: 16 Rating: (0)	Thanks for your answer. I think what you explained to me is for when you want to configure the CP as a customer, but I need a CP is associated internally SERVER and have two-way serial slave (20 and 21). The client sends request for reading my CP internally must have 20 slaves and slaves 21.Cabe highlight both handle different mapping directions, but the only thing I could achieve is to have a DB as a holding register for the slave 20. How to know when the client wants to read the slave 21? Because UNIT in server settings is an output of MODBUSCP and change only when the exchange is completed successfully, also would have to move data to DB (HOLDING REGISTER). I do not speak English, so I apologize for the translation of Google. Thanks again

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3/3/2015 8:41 AM	Rate (0)
Kaulquappe Posts: 3093 Rating: (323)	Hello Joel, I'm rather confused by your last post. Please note: client and master are active - slave and server are passive. So does the S7 act as client or server? This is import for the parameterization. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)
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This contribution was helpful to 1 thankful Users Joel Rock

3/3/2015 3:40 PM	Rate (0)
Joel Rock Regular Member Joined: 12/29/2014 Last visit: 11/12/2024 Posts: 16 Rating: (0)	Hello, I configure S7 as a server. The CP (server) must respond to requests made by the customer. And that client requests data from the CP I want to configure. Requests data to two different UNIT 20 and 21. But not how to configure my CP as a server and in turn manage two mapping directions for UNIT 20 UNIT well as for 21. What I have achieved so far is set only a DB. I hope the graphical help. The red is what I want to configure. Need to know if this application is possible, according to what I read one block MODBUSCP can respond to requests from any UNIT that the client requests. I hope you understand me. Thanks for your answer. Attachment RED.jpg (578 Downloads)
	Last edited by: JoelHuaman at: 3/3/2015 3:46:19 PM
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3/3/2015 6:21 PM	Rate (1)
Kaulquappe Posts: 3093 Rating: (323)	Hello Joel, the CP is no gateway and can't behave as one. So it is not possible to use the same register numbers but different UNIT numbers to get data from different DBs. Due to the Modbus specification the UNIT is only used with gateways. Your screen shot is called "RED.jpg". So I wonder if you are trying to set up a redundant communication. A redundant communication with ModbusTCP is set up by establishing two TCP connections (not one connection and different UNITs). Or did you call it RED because you are going to do the "red colored one"? FB108 is not capable to do what you showed in your picture. FB108 answers to all UNITs, but you can't define data areas depending on the UNIT. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)
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This contribution was helpful to 1 thankful Users Joel Rock

3/3/2015 8:27 PM	Rate (0)
Joel Rock Regular Member Joined: 12/29/2014 Last visit: 11/12/2024 Posts: 16 Rating: (0)	Kaulquappe, Thank you for your response been of great use to solve my doubts about the FB108 block. The network is not reduntante. I have other questions regarding the correct way to use MODBUSCP blocks. In my application I wish my CP to communicate with 4 servers and a client, each on a different port CP. The settings have NetPro the list, there have no doubt, but with regard to the correct way to call the blocks is where I have serious doubts. And I would answer me or confirm the following questions if you do not mind: 1. The OB100 used to initialize Blocks "MODBUSCP". So in this OB I must put 5 "MODBUSCP" each parameterized according to the manual. 2. There should only be a block "MODBUSCP" for each cyclic OB. 3. What is the correct or most efficient way to work several "MODBUSCP" since these blocks are memory intensive work. See chart, Thank You Attachment MODBUSCP.pdf (630 Downloads)
	Last edited by: JoelHuaman at: 3/3/2015 8:30:09 PM Last edited by: JoelHuaman at: 3/3/2015 8:34:05 PM
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