Profibus Master Slave communication

AlfredoQuintero said:

Hello again momo1510:

In case commercial Ethernet interface is OK, you still need an RTOS, socket library and a proper communication stack. There are some free stuff in Githubs and what not, but since they are free they are not tested and they are not current.

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Thank you AlfredoQuintero

The adpaters I need are software ones like those proposed here
https://plc4x.apache.org/. I just need to develop the same thing but using another programming language
Communication stacks can be helpfull for me. I just need some source code that extracts from frames (profinet, profibus, hart, hart-ip) the tags transported by these frames.

Are hart and Hart-Ip compatible protocols or not. I mean if I have a hart device, can I use hart-IP protocol to retreive the data from the hart device? Is it more interesting to develop hart or hart-IP adapters nowadays?

Do you know what is the protocol used by cisco for IoT communications?
Thank you very much

momo1501 said:

Thank you AlfredoQuintero

Are hart and Hart-Ip compatible protocols or not. I mean if I have a hart device, can I use hart-IP protocol to retreive the data from the hart device? Is it more interesting to develop hart or hart-IP adapters nowadays?

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Hart-IP uses Ethernet and IP protocol to encapsulate HART packets. HART uses a very special bus controller which sends an analog current loop for process value and encodes a digital signal within the current loop. So no, they are not compatible.
That is why there are HART modems and HART gateways. I do not believe you can develop such a gateway using off-the shelf products.

Whether HART or Hart-IP is more interesting to develop, I am not sure. The installed base of HART is huge in the process industry. The big vendors of the process industry have agreed on a specification for an Advance Physical layer (APL) which is an extension of the IEEE 802 standard that allows use of twist-pair wire to transmit Ethernet packets complying with intrinsic safety standards. There are no commercial products that I am aware of, and in some years it may be interesting to have such devices, but for now HART is the main protocol for field devices in the process industry. Currently Hart-IP gateways do the conversion between Hart-IP and HART. I would recommend you to visit the FieldComm Group website and learn more about this technology.

momo1501 said:

Do you know what is the protocol used by cisco for IoT communications?
Thank you very much

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Sorry, I am not sure about your question. Normally IoT protocols as I understand them, are above the Layer 3 of the ISO/OSI. Things like OPCUA, MQTT, REST and so on. So I am not sure I can anwser this question as the Cisco routers and switches are at a lower layer, but I may be wrong and I must admit this is not my field of expertise.

According to what you have said, the protocols running on top of UDP and TCP protocols are Modbus, Profinet and Hart-IP. Profibus and Hart protocols have specific implementations that's whay they are no supported here
https://plc4x.apache.org/
Is that right?

I am finally getting the picture of what momo is intending to do.
He needs to retrieve data from Profibus, Profinet and Hart devices.
His idea was (is ?) to listen in to the data between a master and a slave, and then reverse engineer the protocols. All with only using the onboard regular serial or ethernet ports on a regular PC.

Alfredo, do you seriously think that it is possible for a single person ?
Let alone a person that does not seem to know anything about said protocols ?

I think this is never going to fly.

JesperMP said:

I am finally getting the picture of what momo is intending to do.
He needs to retrieve data from Profibus, Profinet and Hart devices.
His idea was (is ?) to listen in to the data between a master and a slave, and then reverse engineer the protocols. All with only using the onboard regular serial or ethernet ports on a regular PC.

Alfredo, do you seriously think that it is possible for a single person ?
Let alone a person that does not seem to know anything about said protocols ?

I think this is never going to fly.

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JesperMP
This is exactly what I need to do?
Do you think that I have another solution to do that?
I have a little knowledge about protocols but my supervisor says that beguinning from scratch is hard working

I suggest you become member of the PI organisation. You should then get access to all documentation for the Profibus and Profinet protocols.

I believe that Peter Nachtwey who is a member on this forum has implemented a Profinet stack on the controllers that his company makes. You could try to contact him for some advice.

JesperMP said:

I suggest you become member of the PI organisation. You should then get access to all documentation for the Profibus and Profinet protocols.

I believe that Peter Nachtwey who is a member on this forum has implemented a Profinet stack on the controllers that his company makes. You could try to contact him for some advice.

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Thank you JesperMP for your advice
Do you think that I can process hart data through the RS232 serial port using a RS232 Hart Modem

I dont have any special experience or knowledge about Hart.
I only once had to set some parameters on a Hart device, and I used a special handheld device that was inserted in the 4-20mA signal to do that.

Sounds to me like this is a job for an OPC server, however, I'm not sure the regular OPC servers like Kepware etc. have Hart IP.

momo1501 said:

Thank you JesperMP for your advice
Do you think that I can process hart data through the RS232 serial port using a RS232 Hart Modem

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It is not possible because the physical layer of HART is NOT RS323. You need a HART modem, as I explained before

JesperMP said:

Alfredo, do you seriously think that it is possible for a single person ?
Let alone a person that does not seem to know anything about said protocols ?

I think this is never going to fly.

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I seriously think it is not possible for a person unfamiliar with industrial protocols to do what he needs. As I described in detail in a previous post of this thread, this is an undertaking for a team of hardware, firmware and tester team, tenths of thousands of US$ worth of development cost for each protocol. The fact I had to explain again that HART does no use RS232 makes me suspect he is not even familiar with ISO/OSI reference model, and if this is the case, that would be the place to start his study.

If he needs to communicate something in the shop floor, he should buy a proper gateway from Prosoft or HMS Networks. If he wants to compete with these guys, wish him a lot of luck, as it will be needed

Hi,

my 2 cents,
If you want to analyse Profibus_DP you need a profibus_DP master, a profibus cable and a profibus_DP slave. You are able to use an oscilloscope to see the pulses over the RS 485_bus. The Profibus protocol is so complicated, without very deep knowledge of it you can't do anything with it. What you need is a profibus analyser like profitrace or so to see and encode the messages. Even then it is not easy to understand the messages. This will be a very expensive test for you.

For Hart protocol you need a special modem because the data is FSK modulated on top of the 4-20 mA signal. These modems are availlable in USB and serial RS232 form.
so you need a software logger to see the serial data over USB or serial.

Dear all,

Thank all you for your valuable suggestions
Now I have a 1214C Siemens PLC. I would like to know please what type of data I can retreive or send to that PLC?

Thank you

Hi momo1501
Maybe have a look at Frontline Netdecoder for industrial communication decoding.

Ray