Mark-

Hello, My notes have (bytes) : 511 - the overhead of 28 per frame/packet. Of course the complete frame/packet is larger because of the wrapping layers. Are you creating a 'driver' or using PLC instructions for the operations? As Ken says, if the latter I am not sure the packet size is a limiting factor. If the former, the packet size is of importance.

Hello, >What does the ^ symbol represent..??? Exponentiation a ^ b means a raised to the power of b (a ^ b is more commonly written ab. The symbol ^ is generally used in programming languages where ease of typing and use of plain ASCII text is preferred.)

Hello, PeakHMI can perform the task.

Hello, Thanks for the answer. >i don't wont to buy the control because it's expensive I assume you are referring to software cost. What do you consider expensive? How much money is too much money, for a HMI software suite?

Hello, Might I ask, why are you wanting to write something in VB and not use an "off the shelf solution"? School? Learning? Challenge? Nothing off the shelf fits your needs? Cost? Just wondering.

Hello, This is what I have in my notes. Glancing at the source code they look correct.

Hi, FX ASCII protocol is a mixture of octal, decimal, hexadecimal and ASCII. There is also two addressing modes. I have only used the extended mode. When I wrote the driver I made some blocking sheets. This was one part regarding reading data. It should be right. Use PeakHMI in demo mode and issue a read while monitoring the serial port if it does not work for you. The stream from PeakHMI will be correct.

Hello, If you are planning on using a PC running a MS Windows OS, PeakHMI might be a good solution for you.

Hi, I said to use PeakHMI demo installer, create the read, capture the read response and then look at the send and response data because the PeakHMI driver does create the proper packet.

Hello, 0x0c,//timer开始的长度 0x00, 0x0a,//timer 0x00, Not sure why you have this twice for the CPU monitoring timer, but I stopped looked when I got here. ASCII is two bytes, Binary is one. Download the demo installer of PeakHMI and install it. Create a project and in configuration mode create a read for the data and use the test button to check the read. Using WireShark capture the packet and look at the bytes.

Hello, PeakHMI might be a good fit.

Hello, PeakHMI uses the system clock to time stamp the trend (data log) values. Each day, at midnight, it creates a new file for the next 24 hours for the data point. You can then select any point from any day and view the trend. For example, you trend the water flow for three days. You can then plot all three days in one trend graphic.

Hello, >I’ve noticed my PLC topic configurations in RSLinx have the “Polled Messages (mSec)” parameter (Data Collection tab) set to 1000ms. However, my OpenOPC clients set the update rate argument to 100ms whenever they read anything, which I thought would override the update rate specified in the RSLinx topic configuration, is that correct? No, the server is allowed to return the best time it supports. You ask for 100, the server returns 200, that is the best the server can do. >- I am seeing active topics/groups hanging around in RSLinx after I've closed all OPC connections (which looking at the OpenOPC code, should remove all groups: “self.remove(self.groups())”). I'm not really sure what is going on here? Per the specification removing groups marks them as removed. Then the server determines when to "delete" the group. There are several reasons a server will delay in deleting the group. > i) How can I figure out what is causing this? That can be tough. Logging OPC client actions and responses would be a start. > ii) Is it logical to think that this could be related to the above issue where some groups aren’t being removed? If the client is sending bad values for group handles then yes, the server only acts on the values from the client. > Desc: A DDE/OPC Client has passed an invalid server handle while attempting an Async IO Read call. Handle value is 0x79ac130. Ouch. Something is out of sync or misconfigured. As to the read delay; there are several ways to get data from the server sync/async read and cached or not (direct). Depending on the configuration this may be the cause of the delay. My2c.

Hi, OK I was looking at the base address value and not the read code value. The read code for CS/CJ CIO area (word size) is 0xB0. >Do I have 2 possibilities? Using 0xb0, read one word and read 1 bit of that word. Or read exactly 1 bit using 0x30. That is correct. You get 16 bits in one word or one byte that is 0 or 1 for the bit. PeakHMI uses the word access mode. Most times, more than one input is needed and it is more efficient. If only one channel is needed then the over head is just one more byte returned. I am not sure all the address fields apply to TCP point to point. If going through some protocol router they might be needed. In our manual it reads: Node number The node is normally the same as the last digit of the IP address. Some devices allow zero (0) for automatic node assignment. The HMI uses the node value returned with the connection handshake. Network and unit default to 0.

Hello, There are several modes of FINS, 'C', 'CV' and 'CS/CJ' Looking at the data dump I see this: Command Data Memory Area Code: Unknown (0xb0) So, the error response validity is questionable. In C and CS/CJ mode, there is no memory area 0xb0. In CV mode the auxiliary area code is x0b00. Hope that helps.

Hello, >What scares me... Regardless of the map, that does not show all customers, why does it scare you? >it does not seem As the line above the map says "Some customer locations.". We have happy customers in Wien. PeakHMI is private labled by 5 companines and sold all over the planet. By the by, a single dot does not represent/indicate we have only one customer in that region.

Hello, PeakHMI has a small footprint with lots of power and supports W7.

Hello, >Is there a decent evaluation version available? Yes. The configuration mode runs for 2 hours and runtime for about 20 minutes. Both can be restarted. The download link as well as videos and demo projects are on our website. http://www.peakhmi.com/

Hello, > can provide multiple data in different day, but same time period? Or any third party software can do this? PeakHMI can display the data it has collected over X days.

Hello, PeakHMI can accomplish that task.

Hello, >Not completely sure what you mean by "Supporting the IEC standard". That is not what he wrote. He is aksing about an OPC server that supports the "IEC 60870-5-104" communications protocol. We have considered adding it but the lack of demand has prevented it.

Hello, > how doea the slave knows that data to be read in place in 40001 That is part of the data packet from the master that is defined in the MODBUS protocol. The master can issue a read or a write that includes the type of register 0,1,3,4, the beginning register and the count of registers. Along with protocol required packet wrapper values.

Hello, > for the various types of CIP protocols, I think this could get complicated if you skip the processor. You need to separate the transport layer from the data the transport layer carriers. TCP/IP does not care about CIP addressing. In this discussion, each card on the backplane, that needs to, must decode the message and do whatever it does. Some message are not for the PLC or could be for a PLC in another rack that is accessed via another media type.

Hello, Just for discussion, why do you think the network does not extend across the backplane from card to card? Protocols, like CIP do not care or have any requirements about the media they are carried on. CIP/TCP/etc. are carried on wire, fiber, microwave, short wave, radio wave, etc.. You and I could have a string and two cans and use the CIP protocol. I would say the value of the bytes in the correct order and you would decode them and vice versa. The chassis could be an extension of the wiring in a TCP network. It is not uncommon for the backplane of the PLC to use a multi-drop serial bus to connect all the cards.

Hello, CIP is made up of several different protocols. They share the same seven layer framework but are not all compatible with each other. TCP is the carrier protocol. CIP is wrapped in a TCP layer. Take the web that you used to post messages. The messages go out your computer on TCP but the browser was using the HTTP protocol to actually send and view the messages SMTP and POP3 are used to get/send your email, assuming you are not using a browser mail client. The wiring/signals is like the train tracks and the train is like TCP. The tracks and the train to do care what is in the train cars, they move the cars. CIP, MODBUS, DNP3, etc. can all ride on the train because the way TCP works.