Can FINS Protocol on serial link

[Eric Apperley 0]

The scenario: - Host computer connected to the RS232 port on CPU (CJ series or similar). This is a direct one-to-one connection, not networked. Question: - Can FINS protocol be used on its own across the serial link without encapsulating within the Host Link protocol "text" area? (Sorry, found this aspect confusing in the W342 manual). Eric

[JeanPierre 0]

I've been trying FinsGateway Trial 2003. No problem http://www.plcsoft.ne.jp/soft/Eng/T_Trial2003_E.shtml Serial Communications and FINS Network The communication functions that FinsGateway provides are based on the FINS network model. This section explains how FinsGateway communicates with serial devices based on the FINS network model. Unit Number and FINS Network For Host Link (SYSMAC WAY, SYSMAC WAY-CV) and CompoWay/F, a unit number is assigned to distinguish each device connected to the serial cable. In FINS, communications are handled by network address, node address, and unit address. For the FinsGateway SysmacBoard Unit, the serial line is treated as a network, and that network is assigned a FINS network address. In other words, the computer COM port is considered one network. In FinsGateway, a device that can be distinguished by its own Host Link or CompoWay/F unit number is treated as a node in the FINS network. However, the Host Link or CompoWay/F unit number, and the FINS node address do not have to be the same. The Host Link or CompoWay/F unit number and the FINS node address can be set independently of each other. The Host Link or CompoWay/F unit number and the corresponding FINS node address are set in the SerialUnit Properties, COMx dialog, in the Node tab. Be Careful: The Host Link and CompoWay/F unit number 0, which cannot be used in FinsGateway is preset to be node address 240. In FinsGateway serial communications, the unit number of the FINS address has no meaning. However, to be consistent and compatible with other networks, it is recommended to set the unit number 0 for serial communications.

[Nibroc 4]

... FINS commands can be transmitted serially to the PLC via either: 1. Encapsulation within 'Hostlink' ascii strings as per CS/CJ communications manual 2. Via Toolbus protocol (not fully documented (I haven't seen a toolbus manual) 3. Use FINS Gateway Notes: Toolbus is a binary protocol which sends FINS commands with a toolbus header (prefix) and checksum (suffix) added. It is more efficient than the hostlink method as approx half the data is transmitted (binary vs ascii) and less ascii / binary conversion may be needed depending on the implementation. I have written various VB / C# scripts using either protocol and both require a similar level of development to implement. FinsGateway: This is a middleware software which provides FINS communications services between PLC's and PC's via various hardware networks (ethernet, controller link, serial). Not sure how to direct FINS commands to FINS Gateway using VB or C - interesting as it may be quite easy. Also not sure how long FINS gateway will be around, as it 'stands alone' from the 'CX' series software - perhaps one of the Omron gurus could tell us ? Nibroc Edited 5 Sep 2006 by Nibroc

[BobB 58]

It will have to be for a while one would think as Omron have not released (to the best of my knowledge) CX-Server to the SCADA community yet. Citect asked for access to it some time ago but this was not on Omron's list of priorities at the time.

[Eric Apperley 0]

Nibroc, Does the FINS gateway actually ensapsulate the FINS command before sending it out on a serial port connection to the network (i.e. does it prefix the command/response block with "@" + Node No + "FA" + response delay) or does it send it as raw FINS ? I can't install the FINS gateway for this application as I'll be using a handheld pocketPC device. Eric

[Nibroc 4]

Eric, The serial port on the PLC will respond to either: 1. 'Host Link' or 2. 'Toolbus' Depending on the port configuration. FINS commands transmitted over the serial line are encapsulated: with 'Host Link' header, checksum and terminator (Host Link Method) or 'Toolbus' header and checksum (Toolbus Method). so to answer your question the answer is yes (or else the PLC would not respond).FINS gateway is not a suitable method for a pocketPC device as it will not run on a pocketPC. You will need to program the PocketPC to 'encapsulate' your FINS commands per 'Host Link' or 'Toolbus' protocols. To do this you will need to create an algorythm to add the header, terminator and appropriate checksum to outgoing messages. Received messages will need to be stripped of their header, terminator and checksum. It is also prudent to confirm received messages are valid by comfirming the received checksum is correct. I prefer to implement the Toolbus protocol: 1. The checksum algorythm is simpler 2. No need to convert data to/from binary/ascii 3. More efficient than Host Link (ascii vs binary data transmission) However the 'Host Link' method is fully documented in the CS/CJ Communications manual. Also: Have a look at the Multiway software (download from this site), it will help you to understand the serial communications between PC / PLC (you can experiment with FINS messages etc) Nibroc

[Eric Apperley 0]

Nibroc, Thanks for the response. Yes, I was aware of the fact that the FINS gateway wouldn't run on a pocketPC device, hence the questions. I do understand how to do the encapsulation for FINS and suspected I'd have to do that for the RS232 port for the reason you mentioned, but just wanted to confirm that was the case. One of the previous responses on this thread was a bit hazy. I can use FINS if required, and I have managed to successfully construct and send FINS messages via Host Link and obtain valid responses. However there's 32767 words of data to transfer with all the protocol overhead so as you say binary makes a lot of sense, especially being a battery powered device. Given that fact, what I would like now is a URL to a Toolbus Protocol manual. Is there in fact a Toolbus Protocol manual or protocol description available to industry (i.e. outside of OMRON themselves)? Eric

[Nibroc 4]

... Eric I haven't seen any actual documentation for 'Toolbus', however it is not hard to 'figure out'. (maybe one of the Omron people can point us to documentation for toolbus???) Message format: Toolbus Header, FINS Header, FINS Command, Checksum. Toolbus Header: AB 00 xx (where xx is number of following bytes in message including checksum) FINS Header: per FINS manual W342 Section 3-3-1: ICF RSV GCT DNA DA1 DA2 SNA SA1 SA2 SID FINS Command: per manual W342 section 5-3 FINS Checksum: sum all bytes of message to form 16 bit (two byte) checksum (will have to look up to check if it is all bytes in message, or all bytes post the toolbus header) All data transmitted is binary, PLC port should be set to toolbus (default for peripheral port), 8,1,none - recommend 115200 baud if stable. Have you downloaded Multiway? http://forums.mrplc.com/index.php?autocom=downloads&showfile=559 Nibroc

[Eric Apperley 0]

Nibroc, Thanks for the details that you've fathomed out - that is appreciated. Yes, I have downloaded and run the Multiway program - it is a useful application. I agree that I could use that to reverse engineer the Toolbus protocol etc..... However, I was hoping that somone at Omron would "step onto the plate" and front up with the Toolbus protocol specification. I don't believe that expecting users to spend time reverse engineering the protocol makes much sense (unless there's a good commercial reason for making it proprietary or a technical reason for users not employing that that protocol). It makes even less sense when the overall scenario is taken into account - I'm not being reimbursed for my time on this project and the entire project is a request from the local OMRON office. I'm enjoying the work on the project but I've got enough "challenges" on my hands with the issues arising from .NET bluetooth mobile device development. Anyway, I'll battle on next week following your lead. Again, thanks for your sharing of knowledge. This is a one of the most helpful forums that I have posted to! [Perhaps Jay can comment on the availability of Toolbus protocol documentation] Eric