Mark-

Hello, > I think this is getting clearer now. Good. > So in terms of the OSI Reference model, DNP 3 is an application layer protocol? Except DNP has and uses an application, link layer and a one byte transport layer. ;) >The meaning of the DNP transport, link layer and application layers, are all of these DNP specific? i.e. not related to the OSI definitions of transport, link layer and application? No. The application layer and link layer perform the same task. The transport layer is a bit different. From the spec: “The ISO (International Organization for Standardization) defines a communication architecture that separates functions into seven layers called the Open System Interconnection (OSI) reference model. DNP3 protocol is based upon a simplified model termed the Enhanced Performance Architecture (EPA) that consists of only three layers: Application, Data Link and Physical.” Using the OSI model, many protocols use 1 or more layers. Ethernet/IP uses all 7. MODBUS uses 1. Good luck, Mark http://www.peakhmi.com/

Hello, Your welcome. > 1. In terms of encapsulation of the DNP 3 protocol on a SCADA system runni... It seems this is becoming much more complicated then it is. The application layer, link layer and one octet of transport layer are part of DNP regardless of any other protocol. DNP does not know anything about protocols that transport DNP information and the transport protocols do not need to know anything about DNP. Look at it as a train made up of many cars. The cars are connected and go from point A to point B based on the rules of the train. DNP puts information in the cars in a defined order (the protocol). How DNP segments that data does not concern the train and its cars. For example: HTTP, FTP, STMP are all protocols that can be implemented and TCP can transport the data. TCP does not know anything about the protocols it carriers. TCP does not know what physical media carriers its packets and what its rules are. From the bottom to the top, all the layers ‘wrap’ the data and generally no nothing of the data they ‘wrap’. > If the DNP 3 protocol does not know about the raw value and the scaled value, how is > this information passed to the Master station for display? DNP does not know what the data represents or how it relates to other data and it does not know what the master is going to do with the data. DNP is a protocol and only specifies how the data is encapsulated. From the primer document: Protocols define the rules by which devices talk with each other, and DNP3 is a protocol for transmission of data from point A to point B using serial and IP communications. DNP3 provides the rules for remotely located computers and master station computers to communicate data and control commands. As you see it uses the word ‘data’. DNP does not know what the data represents only its size and in the case of events the time. Good luck, Mark http://www.peakhmi.com/

Hello, protocol: standard procedure for regulating data transmission between computers. I do not know of any definition of 'protocol' that limits a protocol in any manner. Your second question; it depends on what the out-station publishes. DNP uses the 'objects' model to pass data. All the objects are defined in DNP3 Specification, Volume 6, Part 2, Objects. DNP does not know the connection of the three data points you mentioned. Good luck, Mark http://www.peakhmi.com/

Hello, >Does anyone know anything about DNP3.0? Yes, many people do. ;) >1. Is this a protocol as such, like TCP, UDP, IP ... It is a protocol. This might help you: http://www.dnp.org/About/DNP3%20Primer%20Rev%20A.pdf > 2. Is it a framework, e.g. like OSI DNP has two layers. Well 2.01. It has a link layer and an application layer. It also has a 1 byte 'transport layer.' > 3. If it is a protocol, does it live in a layer such as network layer etc... > From reading the description on dnp.org, it seems like it a protocol that works at many layers... See above answers. >Can anyone find the actual format of the protocols, in terms of headers and payloads. Sure. The specification is published. >Why does it pass both the raw and engineering range to the Master Station? Not sure what you mean by this. There are many different objects in the DNP protocol. Good luck, Mark http://www.peakhmi.com/

Hello, I do not know if the manufacture has an OPC server but PeakHMI can communicate with LS and has a built-in OPC DA server. Master-K (LS Industrial Systems (Redundant - Hot Standby) OPC Data Access Server (DA 2.xx) Good luck, Mark http://www.peakhmi.com/

Hello, PeakHMI now has support for ODBC. All dynamic tag data can be saved to a database. And a database can be the source for raw dynamic analog or digital tag data. The number of concurrent database connections is only limited by the hardware. Cheers, Mark http://www.peakhmi.com/

Hello, For PeakHMI the tag count is unlimited. As are the number of devices you can connect to simultaneously, graphics, trends, etc. Others look at it as entries in the database that are monitored. Each input or output or flag subtracts from the allowed number. Good luck, Mark http://www.peakhmi.com/

Hello, >Currently we use mainly Allen-Bradley SLC 500 and Mitsubishi FX-3U PLC's. PeakHMI can communicate with these devices. Good luck, Mark http://www.peakhmi.com/

Hello, I am playing with this card G6L-CUEB at the present and looked at the frame editor. When the switch is set to 3 and the defaults are used the card outputs: 02 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 03 02 50 4F 4E 4D 4C 4B 4A 49 48 47 46 45 44 43 42 41 03 over and over. So, the default serial settings are 38400, 8N1. It appears you can construct frames and send/receive to the card. Doubling clicking on a frame brings up the editor. The frames can be saved and loaded. I have not been able to find any pre-created frames. I am adding support for the Master-K protocol to PeakHMI. I was unaware that Kepware supported Master-K. It is not listed on their website. More investigations. Cheers, Mark http://www.peakhmi.com/

Hi, Thanks for the information. Cheers, Mark

Hello, What are the differences between these two software packages? 9324-RL0100ENE 1 RSLogix 500 Starter (English) CD-ROM 9324-RL0100ENF 1 RSLogix 500 Starter Concurrent Edition The second one is about $100.00 more. Thanks, Mark

Hi, The solution was to use a serial splitter and two 232<->MPI convertors. It is working well. Ciao, Mark

Hello, I have a Siemens CPU 314. It has one port for MPI communications. I need one more port of the same type. The CP340/341 does not seem to be the correct choice. Which card do I need to add another MPI port to the rack? Is it possible? Ciao, Mark

Hi, > If I ask the scientists that are requesting this they will say every second is the resolution they need. That was the heart of the question. Really the request is to have an 86,400 seconds rolling high/low. Me, I would rather see a trend graph of the previous 24 hours. To each his own. Ciao, Mark http://www.peakhmi.com

Hi, I think it is not defined well enough what is wanted. Let us say that at one time the value goes very very high and then goes low and remains low for the next 24 hours. Regardless of the current temp only the highest would be displayed for 23 hours. That does not sound useful. I could be wrong. What is to be the resolution of the value? Millisecond, sec, min, hour? If it is every hour then 24 locations will be enough. Then a comparison for each sample compared to the value in the index of the hour. On the new hour tick put in the current value in the hour index. Then a quick compare of the 24 indexes for the value to display. Just my 2 cents, Mark P.S. Of course the low would be the same structure and function but with the low values.

Hello, I do not recall ever seeing one in any AB PLC. It would be in the status file. I just looked through the manual for a MicroLogix 1000 and an SLC and neither had an always on or always off. ControlLogix might have one but I did not look. So, just make one. Power rail to a latch coil for on and power rail to an unlatch coil for off. Use any address you want. Ciao, Mark

Hello, >We therefore have no alternative but to use pirated software. We don’t want to, but we are left with no choice. Sure you have choices. >If Company A then got 'legal' with us where would we stand? I am not an attorney. You are violating the copyright. The copyright holder could sue for damages. If they were successful then punitive damages would be possible. And in that area the sky is the limit. You state you have no choice. Of course the easiest choice is to not use the software. It is not the other companies fault that your company did not purchase a legal license to the software. >Our management have accused them of holding us to ransom, which is probably true If is not true. They OWN the software. To ransom is to TAKE another’s property and then demand something for its return. You company is using that statement as a justifier to steal the software. Not to be too blunt, your management is at fault. For whatever reason, they failed. Now they are blaming others for their failure. Not very honest. The other company not attempting to find a solution to keep a customer happy is not good karma. Name the company and maybe someone here will have a solution for you. Please do not take the other companies property. In the long run it will hurt your company more. My2c. Mark

Hello, I have not used iFix for years but PeakHMI can send emails. Ciao, Mark

Hello, Not much data to go on. #1 Put limit checks in before the address is referenced. I assume you have a finite range of addresses you wish to r/w using indirect addressing. #2 Jump around parts of the code to try and isolate the offending rung(s). #3 Find a way to log each address before it is referenced. #4 I do not recall if possible on the ML but try single scan testing. If not set up a switch to jump to the offending code under your control. Of course this all depends on being able to execute the program/make debugging changes without harm to the machinery or people. Good luck, Mark http://www.peakhmi.com/

Hello, That would depend on the type of output on the PLC and the other equipment. Mark

Hello, You could have a look at PeakHMI. Ciao Mark