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Assigning wire tags

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What is a good method for numbering/tagging wires? I/O is obvious for wire tags as is L1 to the MCR and 3 or 30 afterwards. This seems pretty standard on American machines. What I have is a project involving a bunch of interconnection between safety modules, safety relays, and interfacing with the processor. My modules have terminations to OSSD1, OSSD 2, EDM 1, EDM 2, FSD 1, FSD 2, Y1, Y2, Y3, Y4, etc. Since Y1 connects to OSSD1 I have considered Y1/OSSD1 for a tag. Another thought is simply starting @ a block of numbers. This wire could be 1000 and move on from there. Is there a standard for such interconnection? We have several machines in house that have I/O tags as simply a number. I: 2/04 might be something like 168. This is a real pain for troubleshooting. I would have to get the prints out or go to the rack and look for 168s address. This OEM has since moved to using I: 2/04 which makes tracing much faster and easier when doing online troubleshooting. Any thoughts? I don’t think NFPA 79 went into great detail on this. Luke

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This is an important topic and I hope it gets several responses. The importance of wire numbering is often overlooked. I've been doing this work for over 30 yrs. and have yet to find a method that combines all of these factors: low design costs, ease of troubleshooting, and the ability to logically insert/add a wire number. Usually you can get two of the three. Personally I believe the wire# for PLC inputs and outputs should be the PLC address. Granted, tag based PLC's like ControlLogix make this almost impossible. For ease of troubleshooting and design of hardwired circuits, I like making the wire a combination of the print's line # plus 01, 02,03, etc. for the first, second, or third wire on that line. Change the wire # everytime it goes through a device. Example 3204 is the 4th wire on sheet 32 (or AB3204 if prints are divided into sections). The drawback to this is it gets expensive during the design phase when things are inserted or deleted. AutoCAD Electrical makes changing #'s easy. One customer has us use the TO and FROM terminal #'s on every wire. This makes for some very long wire #'s but can make it easy to troubleshoot. Example: TB14-07/TB21-05 or if on an I/O module TB32-47/SLT07-13. The problem arises when trying to wire a PB or device w/o terminal numbers. Another way is to have wire# charts among the first pages of your prints and when adding a wire# you put an X in the chart. The drawback is duplicate #'s will show up if people aren't dilegent about using the X's. Sorry for being long winded, but it is an important topic.

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My preference has always been page number and Grid number The left verticle side of the page would define all the grid line numbers with a horizontal grid at the top for letters. This is opposite to mechanical type drawings. The wire number would be defined as xxxyyz xxx - The current page number yy - The grid line number where the wire Starts z - A number that is incremented everytime the wire goes through a device. Device tags for components should follow the same conventions. As an example if this was page 030 your wire numbers and Device Tag would be as follows: 00 01 030021 CR02021 030022 02 --------------------------------| |----------------------------------- 03 04 05 06 07 08 09 10 Hope this helps. Giz

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I try to use PLC I/O when possible, but Sheet # & Grid # are good too. When I use sheet & grid, sometimes I also want to distinguish between different voltages that may be on the same page. For instance, a wire number might look like this: SSVLLX S = Sheet # V = Voltage Code (0=DC, 1=AC) L = Line # X = Grid # (across the line) I try to keep it under 6 digits because I'd have to buy wider wire labels for the labeling printer than we normally stock. 6 characters works well for me with PLC I/O too (I:0/15) since I don't have racks with more than 10 slots. YMMV.

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Instead of a grid I use line numbers on my electrical drawings, but it is essentially the same. The first two digits of the line number are also the page number. The wire number matches the drawing line on which it originates. A wire retains its number across multiple pages but never across a device. If it ternimates at a PLC point then the PLC address is used. Same for device tags, the device tag contains a reference to the IO address. eg, if the address is Local:5:O.data.o then the device tag will be something like LSH0500 and my program tag will be something like LSH0500_LevelHigh. If a device does not go to the PLC then its tag matches the line on which it originates, eg CR1005 can be found on page 10, line 5 and wire number 1005 will be connected to it. Edited by Alaric

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We generally use Page and Line Numbers for wires and add a letter A,B,C,.... for each terminal junction. 10500 10500A 10500B 10500C all go back to page 10 line 50 wire 0 and A,B,C designates TB's and Junctiions, IO wires are labelled by PLC IO address, L5:I.0 L2:0.1

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A lot of great advice. I am more of an “end user” since my job is industrial maintenance. Work is done on the fly, and unfortunately I usually don’t get a lot of time for planning a project out to as much detail as needed. I do enjoy working on equipment that has excellent prints. We have several Siemens AGVs in the plant and their drawings are probably the best I have seen. They use the same grid and line method you speak of. They also have taken the time to give a drawing for all boards and component locations, communication interconnects, etc. With this project I have already completed all I had time to do was create a spread sheet of my 25 conductor tray cable and the two other multi conductor interface cords. Along with this sheet I also indicated which modules interconnected and assigned the various pin-outs to the terminals. This is where I ended up using the scheme OSSD1/Y1. This represented the light curtain muting module (OSSD1) connecting to the safety relay (Y1). This worked for my purposes of wire assignments and integrating the hardware with in a four hour PM. I doubt if I will be allotted the time to have this drafted as mentioned in the previous postings. I hope those that follow behind and trouble shoot can glean from looking @ the hardware literature and the way they are tagged. It was defiantly not a résumé building print. I have to say that after 12 installs on six differing Palletizers it went well and has been functioning w/o complaints from those that operate them. It never did occur to me to grab one of the equipment OEMs prints and start with one of their blank pages. After working and troubleshooting a machine for six years prints are seldom referred to since I know where most every thing is terminated. Trouble shooting also usually just involves getting online to the PLC with the laptop and working from the I/O back. I am not savvy with Auto Cad nor will the plant outlay the funds for any add-ons for print documentation. Is there a “cheap” alternative out there for drawing schematics and diagrams? Thanks to all for posting. Luke

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I use Smart Draw http://www.smartdraw.com/. When I am at the machine with my laptop making a modification or finding someone elses modification. I then send them to a local company that then converts them to Auto Cad. I have been doing this for awhile now so the company I use knows what I will want added without me having to put it on the drawings. The package is small enough that I can run my PLC software and it at the same time.

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i have not seen or tried it myself but i've heard positive things about http://www.progecad.com/ (free version available, works with DWG files directly so no need to import/export...) did anyone here try it by any chance?

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I have always labeled the IO cards on the print 1,2,3,4 etc. and added the address to it slot 1 output 0 would be wire number 100. All of my DC is 50 - 99. AC misc and control is x1,x2,1-49. Hope this helpsand doesn't sound to silly.

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Well everyone has there own situation and problems to solve. For me 64 Do, 64 Di, 8 Ai and 4 Ao. Using Flex IO, I assigned good descriptors to the Flex IO so anyone coming after knows what the hell is going on. Nothing worse than spending 30 minues scratching your head over an overly complex wiring system. The hint sheets/records always seem to be the first thing missing. Wires are assigned in ref to there Flex Tag.... ie D0:I:12 (Discrete Module 0: Input: 12). Works for us as when on the end of the wire you can monitor the tag and see the result.

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I like to use page and line numbers then increment each wire number on the same line. For PLC hard wire, use the I/O Address. For Remote I/O I have assigned internal bits as the I/O address at design time. For some of the I/O such a as devicenet you don not always know the address until you configure it on line then it is too late if it is incorrect. By assigning the generic internal address the configured I/O just gets re-mapped in the code. Giz.

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I agree with you regarding your use of (your example) "Y1 connects to OSSD1 I have considered Y1/OSSD" I do precisely this when wiring safety circuits e.g Sta30 OSSD1 or Sta30 X1 or Sta30 FGR1 etc. It makes it a lot easier to troubleshoot safety circuits when you can read what the wire is and where it is going , as apposed to a number like 3328 or 1004 etc.

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since i am the only one that will ever work on my projects providing that i do label it i will just have a simple 4 digit number like 0354 and on a sheet has the corresponding number with a to / from description since i am the only one that will ever work on my projects providing that i do label it i will just have a simple 4 digit number like 0354 and on a sheet has the corresponding number with a to / from description

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There are two major considerations in developing a wire numbering scheme. 1. Finding the wire on the electrical drawings 2. Ease of replacement of the field device. So, what I tend to do is use a combination of both. If, for example, the safety relay is on line 237 of the drawings, and has terminals marked S11, S12, S21, S22, Y0, and Y1, my wire numbers would be: 237S11 237S12 etc. Also, the device name will include the drawing line number. This way, you can find any wire on the prints quickly and easily, and the field tech can replace any device easily without having to have the prints or write down all the wire numbers. JMHOO Paul For PLC I/O, I use the PLC address. For Controllogix I use a format that indicates rack-group-slot-point. Edited by OkiePC

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