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problem for roaming of MP 277 IWLAN

Created by: Wacky at: 6/23/2010 12:14 PM (4 Replies)

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6/23/2010 12:14 PM	Rate (0)
Wacky Posts: 60 Rating: (2)	Hi guys, I have a similar problem for roaming ofMP 277 IWLAN. I have 2 Scalance W786-1PRO with same SSID config, 802.11g, with different channels (1 & 6), both in AP mode and wired to a CPU314C with CP343-1. I found that the MP277 responses too slow when I walk from 1st scalance to 2nd scalance. During walking from 1st one to 2nd one, I used the MP277 to ping the PLC. At the beginning, it continues to ping with PLC successly. After I leave the field of 1st scalance, the ping appears error (this is correct). And then, I checked the MP277 WLAN is connected to 2nd scalance, but I cannot ping thePLC correctly. It takes about 5 mins toclose the connection automaticallyand reconnect to 2nd scalance, then I can ping the PLC again. I have tried touse my notebook with wireless connection to do the same test above. It takes few seconds to recover the connection and ping correctly again. Any improvement setting can be done in Scalance or MP277 for solving the above problem? Splitted from Two APs and Mobile Panel Com problem.
Wacky Posts: 60 Rating: (2)	Last edited by: O_Moderator at: 6/24/2010 1:29 PM new subject after splitting
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6/23/2010 1:00 PM	Rate (0)
INS Gold Member Joined: 4/6/2006 Last visit: 2/5/2024 Posts: 604 Rating: (56)	Hello Wacky, Thanks for this explanation. Could you tell or the devices cover the same area partially? Or does it loose the connection first and then you need to walk to the other zone? Are the 2 channels free of interference or are there other overlapping devices in the same area? If so you could think about using 5 GHz channels if allowed in your country. What kind of security settings did you use? Did you already tried the same setup without security? Is it faster? If so I would advice to setup the MP277 IWLAN again by reinstalling/reloading the Operating System and setting up the project again.
	Best regards, INS
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6/23/2010 2:10 PM	Rate (0)
Wacky Posts: 60 Rating: (2)	Hi INS, The two scalanes are designed to cover an area to make I can take the MP 277 IWLAN to look on the PLC when I walk though this area.Is it better to use 802.11a (5GHz) which makes theMP277 reconnect faster? I am using WPA2-PSK, AES, for the security. The MP277 is just purchased from Siemens, so I think the OS is most updated. I need to check about the OS version again and tell you about that. As I said before, I check the WLAN log of MP277 during the test. It seems to authorize to a wrong MAC address of scalance. e.g. When I stand under 1st scalance, the signal is excellant and it shows connected to 1st scalance MAC address. Then, I walk forward to 2nd scalance, the signal becomes low or very low under the 2nd scalance. I check the log that it is still connect to 1st scalance since the MAC address I checked. For few seconds, the signal becomes excellant again. I think it is connected to 2nd scalance, so I check the log and it shows it authorized to 1st scalance's MAC address. Since the MP277 has no more diagnostic information for me to check, such as connected channels, etc. , I cannot make sure it is connected to which scalance. For the above situation, I think is the MP277 OS (Windows CE) problem for fast roaming.
Wacky Posts: 60 Rating: (2)
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6/23/2010 2:29 PM	Rate (0)
INS Gold Member Joined: 4/6/2006 Last visit: 2/5/2024 Posts: 604 Rating: (56)	Hi Wacky, The two scalanes are designed to cover an area to make I can take the MP 277 IWLAN to look on the PLC when I walk though this area.Is it better to use 802.11a (5GHz) which makes theMP277 reconnect faster? >>> Depending on the environment I would say that this could enahnce since there is normally less interference in 5 GHz then in 2,4 GHz. I am using WPA2-PSK, AES, for the security. The MP277 is just purchased from Siemens, so I think the OS is most updated. I need to check about the OS version again and tell you about that. I didn't meant to update the OS because of a newer version. I'm having doubts in possible configurations errors which are left in the system due to testing time. This would be solved with a new panel. Try to set the system up in steps. First new OS, then new channels (5 GHz), then security. As I said before, I check the WLAN log of MP277 during the test. It seems to authorize to a wrong MAC address of scalance. e.g. When I stand under 1st scalance, the signal is excellant and it shows connected to 1st scalance MAC address. Then, I walk forward to 2nd scalance, the signal becomes low or very low under the 2nd scalance. I check the log that it is still connect to 1st scalance since the MAC address I checked. For few seconds, the signal becomes excellant again. I think it is connected to 2nd scalance, so I check the log and it shows it authorized to 1st scalance's MAC address. Since the MP277 has no more diagnostic information for me to check, such as connected channels, etc. , I cannot make sure it is connected to which scalance. To check this used the Web Based Manager from the Scalance devices. You could check the client list of both devices to see what happens. Since you use the same area to be covered with 2 AP's it coulc be that it's hopping from one to another because the signal quality is round the threshold used by the panel to decided or it should roam to the other AP. For the above situation, I think is the MP277 OS (Windows CE) problem for fast roaming. I agree on your point that Windows CE is in standard version not optimal for WLAN and Roaming. Even Windows PC's have a delay of multiple seconds before the AP List is refreshed automaticaly.
	Last edited by: INS at: 6/23/2010 2:31 PM Best regards, INS
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6/24/2010 12:05 PM	Rate (0)
Wacky Posts: 60 Rating: (2)	Hi all, My problem was solved and now here sharing with you guys. First, I tried to change 5GHz, but it is failure. After that, I set the scalances without security config for WLAN. It is successful. I walk though the covered area and it will change the wireless connection, but it still need about 10-15 sec to finish the reconnect. Finally, I have 3 Scalances and 1 TP-LINK AP. Both APs work with the Mobile Panel. Final setting: - 802.11g (2.4GHz) - SSID without broadcast - No security for wireless connection - different channels for differentAP(I set the channels as 1, 6, 8 and 11) Finally, thank you INS's advances.
Wacky Posts: 60 Rating: (2)
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