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Rcoax IWLAN

Created by: kwtang at: 12/4/2014 5:00 AM (11 Replies)

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12/4/2014 5:00 AM	Rate (0)
kwtang Posts: 6 Rating: (0)	A very good morning to all expert I'm having some communication error on this rcoax iwlan. In my cpu diagnostic buffer is show "IO station Failure". In my case, the application is overhead conveyor for car plant. My configuration is; On master side,1 master cpu connected to two Access Point. Master cpu is 1513-1 >>AP1&2 (W788-1 M12) >>power splitter x2 >>5G rcoax cable 50 meter on each segment. This will forming a eclipse having total distance of 200meter. On slave side, I have 10 set of slave cpu. Each cpu having its own client and antenna. And each slave cpu having 64 DI, 64DQ and a TMPos Input 2 module (reading encoder pulse) Slave cpu is 1511-1>>client(w748-1 m12)>>antenna ANT793-4MN All are ipcf enable with update cycle set to 128ms. Communication used is Profinet I-device. On Tia portal update cycle being set to 128ms. On the slave side,there is one travel motor which move the carrier forward and two hoist-front and rear to lift car body up and down. Whenever those motors start to stop, there will had this "IO station Failure" error. Recovery time for some slave cpu is few milisec.Some take up 10 sec to return to normal. While 2 slave cpu won't recovery till I restart CPU. Any idea what causing this error? And what are the solution?
kwtang Posts: 6 Rating: (0)
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12/6/2014 8:03 PM	Rate (0)
Late Platinum Expert Joined: 1/7/2006 Last visit: 11/17/2023 Posts: 2705 Rating: (318)	kwtang I'm having some communication error on this rcoax iwlan. 1. In my cpu diagnostic buffer is show "IO station Failure". In my case, the application is overhead conveyor for car plant. My configuration is; On master side,1 master cpu connected to two Access Point. 2. Master cpu is 1513-1 >> AP1&2 (W788-1 M12) >>power splitter x2 >>5G rcoax cable 50 meter on each segment. This will forming a eclipse having total distance of 200meter. On ~~slave~~ device side, I have 10 set of ~~slave~~ I-device-cpu. Each cpu having its own client and antenna. And each ~~slave~~ PN-cpu having 64 DI, 64DQ and a TMPos Input 2 module (reading encoder pulse) ~~Slave~~ I-device-cpu is 1511-1 >> client (w748-1 m12) >>antenna ANT793-4MN 3. All are ipcf enable with update cycle set to 128ms. Communication used is Profinet I-device. On Tia portal update cycle being set to 128ms. On the ~~slave~~I-Device side,there is one travel motor which move the carrier forward and two hoist-front and rear to lift car body up and down. 4. Whenever those motors start to stop, there will had this "IO station Failure" error. Recovery time for some ~~slave~~ I-device cpu is few milisec.Some take up 10 sec to return to normal. While 2 slave cpu won't recovery till I restart CPU. 5. Any idea what causing this error? 6. And what are the solution? Hi, To 1. A device is from the PROFINET. To 2.What are the antenna cable lengths to the power splitter and to the RCOAX? Every 5 meter give 3dB loss of signal (3dB is the half of your power from the AP). To 3. If the AP is set on 128mS then it could reach with iPCF all 10 I-Devices, but the update time for the I-Devices must be some faster. Like 64mS. To 4. If the trouble starts when you Stop a motor then it is very important to check your power circuits, what is connected to what and what's done with the M and the Earth of the different devices in the cabinet. To 5. Are there other IWLAN on the 5GHz, which channels are youusing? To 6. Difficult to say, if it is always 4. that initiates the issues then please check there everything very well beginning with the stations that are only back online when restart the hole CPU. What's coming in the diagnostic buffer of thePROFINET Controller CPU and the I-Devices?
	I hope that the answer will help, if you have still questions, don't hesitate to ask me. All the best, Late Never say never, think in solutions, not in trouble......
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12/9/2014 8:22 AM	Rate (0)
kwtang Posts: 6 Rating: (0)	Hi there, 1. It is the error pop out from the cpu 1511 when i go online in TIA portal. 2. antenna cable to power splitter is 1m.From power splitter to rcoax cable is 1 meter as well 3. For I-Device update time in TIA Portal, I had try all the range from 4ms to 512ms. It still giving me the same error. 4. All the earth had been check throughly. And we already separate the ac power cable, dc power cable and antenna cable. But the error still there. 5. No. For rcoax AP1 and AP2, I'm using channel 149 and 153. But,nearby there is another different system using siemens wireless W780/W740 with wifi antenna (ANT793-6MN) This system using channel 161 and 165. There is IO station failure error in this system as well, but it recovery very fast-<5msec.So, it doesn't cause any problem so far. And both system having different SSID name, different client name and different ap name. 6. Attach is the screen shot for the error in the master plc and slave plc. As you can see No.24 error occured. And recovery in 0.2sec- No.23. Once recovery, it will follow by this "User data failure hardware component" error. Then, it when back to normal This cycle will keep repeating and repeating.... Can it be interference/noise causing it? I had try to power on the 11th set of client at the ground level without any motors running. Out of expectation, there is no error!! for your info, the rcoax cable is about 8 meter above ground level. So, i was wondering how far the coverage area of this rcoax radio waves? Any idea? At ground level, besides the master plc panel, there is other system panels such as oven, blowers, pumps using softstarter and/or VFD. So, how great is this rcoax cable immune to noise? thanks. Attachment IMG-20141206-WA0000.jpg (159 Downloads)
kwtang Posts: 6 Rating: (0)
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12/10/2014 3:23 PM	Rate (0)
Fafner Silver Member Joined: 3/20/2013 Last visit: 4/3/2024 Posts: 676 Rating: (44)	hey kwtang, that is not that easy without having a closer look at: a) installation b) radiation environment (radar, ...?) c) configuration But let me give a few guesses: First of all please have a look at the following manual (hints about installation, configuration, ...): - RCoax System manual http://support.automation.siemens.com/WW/view/en/21286952 is the installation done correctly, .... - you can decrease the iPCF time to 64ms and have PNIO update time at 128ms. - another possibility is that you get a radar pattern and your AP changes the channel --> longer interruption.
	Last edited by: Fafner at: 12/10/2014 3:25 PM Best Regards, Fafner
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12/12/2014 2:19 AM	Rate (0)
kwtang Posts: 6 Rating: (0)	Hi Fafner, The installation and configuration is fine as i'm getting 80-100% strength when i use the signal recorder. But, it just giving this error. What do you means by radar pattern that change the AP channel? What the counter measure? Thanks.
kwtang Posts: 6 Rating: (0)
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12/12/2014 8:03 AM	Rate (0)
Fafner Silver Member Joined: 3/20/2013 Last visit: 4/3/2024 Posts: 676 Rating: (44)	hey kwtang, first of all: signal strength is not everything. is your signal strength from time to time over the 100% ? that would be too much. you are saying that come PLCs are not coming back after a communication error: do you have problems with the startup or does the communication not coming back? (if you have startup problems it is perhaps not related to your wireless ;) ) can you see the errors in random places of your plant or is it always at roughly the same point? are there other applications around? which channels are you exactly using? is it known to the client that he has only to check 2 channels when he wants to roam? are there other wireless applications around? and: you should decrease the iPCF time (at the wireless components!) to 64ms and have PNIO update time still at 128ms!
	Best Regards, Fafner
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12/12/2014 10:28 AM	Rate (0)
kwtang Posts: 6 Rating: (0)	Hi fafner, It is not all the while the signal strength is >100%. May 20% in 1 cycle. Anyway as suggest I had reduce the transmit power from 20dbm to 10dbm. I had reduce the ipcf 64ms and pnioto 128msec. Now, the signal strength >100% had been reduce to 5%. But, the communication error still there. For some client CPU, I have to restart it. 2 out of 10.but only ocassionly Some automatically recover in msec. 6 out of 10. While the rest take abt 2-5sec to recovery. But, it still automatically recover. On the client fault logs, I saw something like "link down at wlan1" and few sec later "link up at wlan1". This keep repeating continuosly. What are causing it? The whole plant,only 2 wireless application using this 5G. The rest is 2.4G. 1st application is using WiFi wireless having ant793-6mn antenna. using channel 161 and 165. As for this, I am using channel 149(ap1)and 153(ap2). And it is confirm that every client is roaming to this 2 channel. Thanks
kwtang Posts: 6 Rating: (0)
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12/12/2014 11:18 AM	Rate (0)
Fafner Silver Member Joined: 3/20/2013 Last visit: 4/3/2024 Posts: 676 Rating: (44)	hey kwtang, 1. what is the lowest dB level you are getting with the signal recorder? and what is the highest? 2. on client side you can define which channels are to be scanned. please configure this option with your used channels 149 and 153. --> that makes the roaming a lot faster. at the moment your clients are scanning all 5GHz channels before they roam. out of your description I assume that the channels have no interferences?! there you are sure? 3. which clients and APs are you exactly using? MLFB? and e.g.: are you using the newest FW? Which is the used FW-version? If you have the new devices here is the link to the FW: http://support.automation.siemens.com/WW/view/en/102255679
	Best Regards, Fafner
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12/12/2014 5:33 PM	Rate (0)
kwtang Posts: 6 Rating: (0)	Hi fafner, 1.Power at 7dbm,the lowest is -77dbm and highest is -39dbm. See attachment. I had try 9 and 8dbm. but, i found at 7dbm, the communication is minimized. If i reduce further to 6dbm, i will be getting -70 to -85dbm, most of the time. So, I fix it to 7dbm and keep on monitoring it. 2. All the while, my configuration on clients had been set on this two channel only. 3. The Ap is scalance w788-1 M12 (6GK5 788-1GK00) while the client is scalancew748-1 m12 (6GK5 748-1GK00). All the ap and clients frmware had been update to version 4.00.01. This is my first project using this rcoax iwlan. It is gettting me crazy!!! What else can be done? Really appreciate all your help. Thanks Attachment Carrier 8 with 7dbm.pdf (222 Downloads)
kwtang Posts: 6 Rating: (0)
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12/15/2014 8:05 AM	Rate (0)
Fafner Silver Member Joined: 3/20/2013 Last visit: 4/3/2024 Posts: 676 Rating: (44)	hi kwtang, you did not answer one question: are the communication errors more often at special places or is it randomly? kwtang Hi fafner, 1.Power at 7dbm,the lowest is -77dbm and highest is -39dbm. See attachment. I had try 9 and 8dbm. but, i found at 7dbm, the communication is minimized. If i reduce further to 6dbm, i will be getting -70 to -85dbm, most of the time. So, I fix it to 7dbm and keep on monitoring it. the signal recorder file looks good. you can decrease it a bit more, but I think it's OK. (depending on the track. perhaps you should decrease it a bit more to avoid roaming between segments when it is not necessary) please have a check over the WBM. look at the AP and look at the client, please check if they see each other with almost the same strength. (you have to adopt the signal strength on both sides: AP and client.) (you can see this under information -> wlan -> wlan client/wlan AP or sth like that) kwtang 2. All the while, my configuration on clients had been set on this two channel only. very good. that makes your roaming faster. perhaps post your configuration file?! or make some screenshots of the configuration (easier to read). kwtang 3. The Ap is scalance w788-1 M12 (6GK5 788-1GK00) while the client is scalancew748-1 m12 (6GK5 748-1GK00). All the ap and clients frmware had been update to version 4.00.01. newest firmware --> check kwtang This is my first project using this rcoax iwlan. It is gettting me crazy!!! What else can be done? Really appreciate all your help. Thanks ouh, perhaps we should start with the mounting (despite the signal trace is looking good.) You can get some help from the siemens support (limited support is for free, see link). there is a debug file which can be examined by the support to perhaps see reasons for the communication losses. www.automation.siemens.com/support-request Or you can get a specialist on site (ordered for youby your siemens salesman). then there will be some spectral analysis, mounting checks and configuration optimization executed.
	Best Regards, Fafner
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