2/26/2016 10:23 AM | |
Joined: 3/27/2012 Last visit: 9/19/2024 Posts: 179 Rating: (4) |
Hi again, I have a system that has 4 PLC-CPU226 that uses both port 0 and 1, I had to change one of them but what ever I do I can not read data from Port 1!!! 4 different system but do the same and use the same program, port 0 is connected to UniOP screen and work ok with setting of 6900-N-8-1 but Port 1 is connected to DP25 scale and setting is 6900-O-7-1. I checked the setting when I go online by port 0 and is the same as other PLCs... By the way I can not go Online by Port 1 when is in STOP mode (I know port 1 is Free Port set) Even I couldn't go online in the workshop on a new PLC after downloading program!!!! Any body there can help AttachmentChemical_4.zip (399 Downloads) |
Last edited by: AhooraJafari at: 2/26/2016 10:36:31 AM |
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3/4/2016 11:58 AM | |
Joined: 3/27/2012 Last visit: 9/19/2024 Posts: 179 Rating: (4) |
By saying Refereshing the communication when connected to port 1, I mean from communication setting page and It shows Port 1 is known and can see it but as soon as I click on OK an error comes up and says UNKNOWN PORT ADDRESS? ------------------------------------------------------------------ We have 4 system with CPU226 that works very similar to each other and on each one Port 0 is connected to screen UniOP and Port 1 is connected to scale DP25, port RS422 as FREE PORT setting. When I try to change CPU 226 on any of those 4 systems (with New CPU) I will see the problem with Port 1!! that doesn't send the right format and Weigh variable (VW200 in program) always showing wrong weigh... (UniOP has 2 communication port, 1 is RS232 and another one is RS422 that is used on all 4 system) To get around this problem I just swap the 9 pin connector from RS422 to RS232 to make it to work right for any new CPU I use to swap faulty one and I don't understand why I have to change the port on Scale to make it to work the same as the old PLC with the same CPU type!!!! Does it make sense now, if not let me know to explain more By the way I attached the program before and you can have a look to see the port setting. AttachmentChemical_4-PLC-HMI.zip (315 Downloads) |
Last edited by: AhooraJafari at: 3/4/2016 12:05:39 PM |
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3/9/2016 1:20 PM | |
Joined: 3/27/2012 Last visit: 9/19/2024 Posts: 179 Rating: (4) |
Hi Duris_I, Firstly I haven't used any Converter on cable, I normally make the cable I need and on that job is just 2 wires between PLC and DP25 Scale, Pin 7 and 8 on Scale side is connected to pin 3 and 8 on PLC side. A normal cable with 9 Pin connector is used on both sides. I did another project with the same type PLC and Avery Scale but I had to make a cable with Null Modem connection as follow to work right. About writing #2020 to VW0 (12 Bytes) is for end of Reading Cycle to refresh the Value (Cycle time), at end of each receiving 12 Bytes Data we must clear it and start over. I attach another project that I did with different communication cable but doing very similar Job and reading data from Scale and show it on display.
AttachmentButter_SyrupLAST.zip (271 Downloads) |
3/9/2016 1:28 PM | |
Joined: 3/27/2012 Last visit: 9/19/2024 Posts: 179 Rating: (4) |
Communication Cables Pin out Communication cables are normally Null Modem (Cross over wires) or RS232 with different Pin assignment and anybody can make them by checking the connection they need and build it. Any device with Serial Port tells you the Pin allocation you need and the rest is upto you to make it or buy a ready communication cable. AttachmentRS232 Pinout.zip (340 Downloads) |
Last edited by: AhooraJafari at: 3/10/2016 10:15:18 AM |
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