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MODBUS RTU Power Meters to MODBUS TCP Gateway to CPU-300 to PCS7 Plant Bus

Created by: G_R_E_Y_31 at: 6/10/2014 9:18 AM (26 Replies)

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6/10/2014 9:18 AM	Rate (0)
G_R_E_Y_31 Bronze Member Joined: 5/26/2011 Last visit: 11/14/2024 Posts: 456 Rating: (7)	Good day experts! I'm given this task that includes MODBUS to Ethernet conversion as well as CPU-CPU communication via Ethernet also, please see the attached file for the basic system architecture. Can you help me on: 1) S7-300 to S7-400 communication via Ethernet I'm familiar on S7 CPU-CPU communication for Profibus. I've done it via SEND/RECEIVE block(DB address) using a CP on slave as well as via HWConfig(periphery address) using the slave integrated DP port, both by having the slave as GSD file on the master. Would the communication via ethernet/TCP IP just somewhat similar? And can I also use either CP or the integrated TCP-IP port for both master and slave? 2) MODBUS to Ethernet conversion You see that the power meters are using MODBUS protocol, so should there be something like a MODBUS to ethernet converter that I can connect to perhaps a CP 343 or integrated ethernet port of CPU 315-PN/DP? If so, should there also be something like a GSD file for that converter, if there isn't one already on the HWConfig? Any link will be appreciated. If someone is kind enough, can you give me your Hardware Configuration for this said task? I would appreciate it very much. Thanks! Attachment Drawing1.jpg (611 Downloads)
	Last edited by: nicer at: 6/11/2014 9:38 AM Last edited by: nicer at: 6/10/2014 10:23 AM Last edited by: nicer at: 6/10/2014 10:12 AM Last edited by: nicer at: 6/10/2014 9:20 AM
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6/10/2014 9:43 AM	Rate (0)
G_R_E_Y_31 Bronze Member Joined: 5/26/2011 Last visit: 11/14/2024 Posts: 456 Rating: (7)	I've looked into a CPU-315-PN/DP on the HWConfig. On my past experience of CPU-CPU communication via profibus, I've used the "Configuration" tab of the integrated "MPI/DP" port of the CPU. Now I've seen that there seems a similar tab on the integrated "PN-IO" port of the CPU named "I-Device". Can this also be used like the profibus one? But if so, then does this mean that on the master side where you configure the slave CPU-315-PN/DP GSD file, those modules (universal module, master_I slave_Q, etc.) can designate either profibus or ethernet? Or can ethernet communication even be configured by GSD file since the CPU-315-PN/DP GSD seems to be under the Profibus-DP catalog, and none under the Profinet-IO? Thanks.

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6/10/2014 10:35 AM	Rate (0)
TIBI68 Gold Member Joined: 12/1/2009 Last visit: 10/27/2024 Posts: 672 Rating: (147)	Dear nicer, you can find excellentgateways here: http://hilscher.com/products_list_group.html?upg=15&pg=22 There are of cause many other manufactures and solutions. Best Regards.
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6/10/2014 4:14 PM	Rate (1)
Kaulquappe Posts: 3093 Rating: (323)	nicer 2) MODBUS to Ethernet conversion You see that the power meters are using MODBUS protocol, so should there be something like a MODBUS to ethernet converter that I can connect to perhaps a CP 343 or integrated ethernet port of CPU 315-PN/DP? If so, should there also be something like a GSD file for that converter, if there isn't one already on the HWConfig? Hello Nicer, Modbus is a protocol, Ethernet isthe definition of a network. The Modbus protocol for ethernet is called ModbusTCP. Ethernet/IP is also a protocol. GSD files are only used for Profibus communication. According to you sketch, you can use different protocols for the data transfer between S7-300 and S7-400. I expect that the communication to the power meters is ModbusTCP. Then you can use a PN CPU or a CP443-1 and a ModbusTCP library. www.siemens.com/s7modbus. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)
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6/11/2014 9:32 AM	Rate (0)
G_R_E_Y_31 Bronze Member Joined: 5/26/2011 Last visit: 11/14/2024 Posts: 456 Rating: (7)	Hello Kaulquappe, Sorry for the incomplete information. Now I have some more particulars: The power meters that will be used are Schneider Electric PM810. As I've seen in its manual, it is using MODBUS RS 485 (synonymous to MODBUS RTU right?). Due to this, there will be a Schneider Electric gateway EGX300 which converts MODBUS RTU to MODBUS TCP I suppose (although one can point that the PM810 MODBUS RTU can already be connected directly to the S7-300 CPU by having CP341 as MODBUS RTU Master, but this conversion from RTU to TCP was done primarily due to distance concern). Sorry if I cannot upload the manuals for both PM810 and EGX300 due to file size limitation, but I think it's readily available at the web by a simple google. On the CPU-CPU communication, the S7-300, where the gateway for the power meters is connected, is connected to an S7-400 CP343-1 which is then onnected to a plant terminal bus which has ES (Engineering Station/PCS7) and OS (Operator Station/WinCC). The purpose of connecting the S7-300 CPU to the S7-400 CPU is so that the power meters can be monitored to the PCS7 OS clients. In this case, I guess the S7-300 can be simply seen as directly connected to the plant terminal bus. Now, as I've read from some search and as you've said, I can communicate the power meters to S7-300 CPU through the gateway either by CP343 or an integrated PN port. 1) What do you think would be better of the two? 2) Can I use that same port for connection to the plant terminal bus (i.e., to the ES, OS and other PLCs)? Meaning, if I chose either the integrated PN port, or one CP343 of a CPU without integrated PN, I can connected that to both the gateway EGX300 and plant bus SCALANCE? 3) Can I use both integrated PN port and a CP343, say the PN port to the plant bus and CP343 to the gateway or vice versa? What would be better? 4) I have both the manuals "OPEN MODBUS / TCP Communications via CP343-1 and CP443-1" and "S7-OPEN MODBUS / TCP Communications via integrated PN interface of the PLC", would studying this already suffice for me to be able to configure and program the communication between power meters and gateway and the S7-300 CPU after I purchase either 2XV9450-1MB00 (MODBUS TCP blocks for CP) or 2XV9450-1MB02 (MODBUS TCP blocks for CP)? 5) Do you have a particular example of configuring & programming the communication between the said power meters PM810 & gateway EGX300 and S7-300 CPU? Thanks much!
	Last edited by: nicer at: 6/11/2014 9:48 AM Last edited by: nicer at: 6/11/2014 9:44 AM
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6/11/2014 10:20 AM	Rate (1)
TIBI68 Gold Member Joined: 12/1/2009 Last visit: 10/27/2024 Posts: 672 Rating: (147)	Hello nicer, nicer Hello Kaulquappe, Sorry for the incomplete information. Now I have some more particulars: The power meters that will be used are Schneider Electric PM810. As I've seen in its manual, it is using MODBUS RS 485 (synonymous to MODBUS RTU right?). Due to this, there will be a Schneider Electric gateway EGX300 which converts MODBUS RTU to MODBUS TCP I suppose (although one can point that the PM810 MODBUS RTU can already be connected directly to the S7-300 CPU by having CP341 as MODBUS RTU Master, but this conversion from RTU to TCP was done primarily due to distance concern). Sorry if I cannot upload the manuals for both PM810 and EGX300 due to file size limitation, but I think it's readily available at the web by a simple google. On the CPU-CPU communication, the S7-300, where the gateway for the power meters is connected, is connected to an S7-400 CP343-1 which is then onnected to a plant terminal bus which has ES (Engineering Station/PCS7) and OS (Operator Station/WinCC). The purpose of connecting the S7-300 CPU to the S7-400 CPU is so that the power meters can be monitored to the PCS7 OS clients. In this case, I guess the S7-300 can be simply seen as directly connected to the plant terminal bus. Now, as I've read from some search and as you've said, I can communicate the power meters to S7-300 CPU through the gateway either by CP343 or an integrated PN port. 1) What do you think would be better of the two? 2) Can I use that same port for connection to the plant terminal bus (i.e., to the ES, OS and other PLCs)? Meaning, if I chose either the integrated PN port, or one CP343 of a CPU without integrated PN, I can connected that to both the gateway EGX300 and plant bus SCALANCE? 3) Can I use both integrated PN port and a CP343, say the PN port to the plant bus and CP343 to the gateway or vice versa? What would be better? 4) I have both the manuals "OPEN MODBUS / TCP Communications via CP343-1 and CP443-1" and "S7-OPEN MODBUS / TCP Communications via integrated PN interface of the PLC", would studying this already suffice for me to be able to configure and program the communication between power meters and gateway and the S7-300 CPU after I purchase either 2XV9450-1MB00 (MODBUS TCP blocks for CP) or 2XV9450-1MB02 (MODBUS TCP blocks for CP)? 5) Do you have a particular example of configuring & programming the communication between the said power meters PM810 & gateway EGX300 and S7-300 CPU? Thanks much! What is the purpose of the S7-300 ? Just as gateway? If yes, why do you notconnect the modbus slaves direct to your S7-400? Is it possible that you can upload us a complete system design layout of your application (with some information about the distances)? I am sure we will be able to support you with an optimal solution. Best Regards.
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6/11/2014 11:18 AM	Rate (0)
G_R_E_Y_31 Bronze Member Joined: 5/26/2011 Last visit: 11/14/2024 Posts: 456 Rating: (7)	Hello TIBI68, TIBI68 What is the purpose of the S7-300 ? Just as gateway? If yes, why do you notconnect the modbus slaves direct to your S7-400? This actually is my first question when I'm asked to research this task, the answer to me is that the likelihood is that the power meter system will be seperated from the PCS7, so that it will be an independent system. But now that I'm reminded by your inquiry, I ask what this independent system would be comprised of, and I found that it's just for monitoring/analysis of those and only those power meters and the monitoring/analysis software will not actually need an S7-300 CPU. So now, we're considering that, namely, connecting the gateways directly to the S7-400 or to the plant bus SCALANCE switch (where the S7-400 CP443s as well as the ES and OS are interconnected). The possibile concern I'm thinking there then would be that the existing version of CP443 (6GK7-443-1EX11-0XE1) may not be compatible for MODBUS TCP (or could that be possible?). But if so, we can just have new CP443 for the task, together with the driver blocks. The MODBUS RTU slaves on the other hand goes to a gateway first due to a long distance communication (talking about kilometers) where the gateways would actually be first converted to fiber optic or wireless comm. TIBI68 Is it possible that you can upload us a complete system design layout of your application (with some information about the distances)? I am sure we will be able to support you with an optimal solution. Best Regards. I really appreciate your desire to help sir but, unfortunately, it seems that architecture (except the presence of S7-300 station) wouldn't be changed anymore for the setup of the devices I've given is already on process. It was the design of the Schneider power meter supplier themselves, so I guess we can rest assured and focus now to the system integration. Can you give me some advice on my five inquiries (assuming there would still be an S7-300 CPU connected to thePCS7 terminal bus)? Thanks much!

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6/11/2014 12:47 PM	Rate (0)
TIBI68 Gold Member Joined: 12/1/2009 Last visit: 10/27/2024 Posts: 672 Rating: (147)	Its me again, then I suggest you to use a separate CP443-1 in your S7-400 for your communication via Modbus/TCP only andto separate thenetworks. For thecase you need to keep the S7-300add a CP343-1 for the same reason as above. So in any case everybodyshould behappy. Best Regards.
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6/12/2014 10:36 AM	Rate (0)
Kaulquappe Posts: 3093 Rating: (323)	nicer 1) What do you think would be better of the two? 2) Can I use that same port for connection to the plant terminal bus (i.e., to the ES, OS and other PLCs)? Meaning, if I chose either the integrated PN port, or one CP343 of a CPU without integrated PN, I can connected that to both the gateway EGX300 and plant bus SCALANCE? 3) Can I use both integrated PN port and a CP343, say the PN port to the plant bus and CP343 to the gateway or vice versa? What would be better? 4) I have both the manuals "OPEN MODBUS / TCP Communications via CP343-1 and CP443-1" and "S7-OPEN MODBUS / TCP Communications via integrated PN interface of the PLC", would studying this already suffice for me to be able to configure and program the communication between power meters and gateway and the S7-300 CPU after I purchase either 2XV9450-1MB00 (MODBUS TCP blocks for CP) or 2XV9450-1MB02 (MODBUS TCP blocks for CP)? 5) Do you have a particular example of configuring & programming the communication between the said power meters PM810 & gateway EGX300 and S7-300 CPU? Thanks much! 1. I would prefer the PN-CPU for the ModbusTCP communication because it is faster and you are not limited regarding the number of connected devices. 2. yes 3. well, that depends on timing requirements 4. + 5. There is no special sample for these 3rd party devices, but both libraries are installed with a general sample. You can download the demo version and have a look at it. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (323)
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6/13/2014 4:36 AM	Rate (0)
G_R_E_Y_31 Bronze Member Joined: 5/26/2011 Last visit: 11/14/2024 Posts: 456 Rating: (7)	TIBI68 Its me again, then I suggest you to use a separate CP443-1 in your S7-400 for your communication via Modbus/TCP only andto separate thenetworks. For thecase you need to keep the S7-300add a CP343-1 for the same reason as above. So in any case everybodyshould behappy. Best Regards. Why is this so? Is there a possibility that MODBUS communication would interfere with the Profinet or that the new MODBUS communcation would result to added communication load that could jeopardize the existing medium? Since it's not like redundancy for, if one is for the communication to plant bus and the other for the MODBUS devices, one fail of either will have same result (i.e., disconnection to the Power Meter), at least with respect to the metering system. Also, it seems that the overall communication job/load for the CPU will still be the same whether you use a seperate one. Thanks with your continuous reponse!
	Last edited by: nicer at: 6/13/2014 6:52 AM
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