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Comms Loss between HMI and PLC

Created by: Karl84 at: 8/22/2014 7:11 PM (7 Replies)

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8/22/2014 7:11 PM	Rate (0)
Karl84 Advanced Member Joined: 8/28/2012 Last visit: 4/14/2019 Posts: 33 Rating: (0)	Hi, Is there a specific OB or block which deals with a HMI loss. Previously I have experienced comms loss with Profibus using OB blocks but if you remove an HMI, no errors seem to occur. Cheers

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8/22/2014 11:32 PM	Rate (0)
MicroMan Platinum Member Joined: 11/29/2011 Last visit: 11/15/2019 Posts: 1314 Rating: (214)	Hi, There is no OB (as far as I know) dealing with HMI losses. Reason being: Fault OBs are dealing HW errors. Loosing an HMI is not a HW fault for the PLC as the CPU not master of the CPU-HMI com. Usually the HMI set up with S7 connection and setted as only master on the bus. Anyway I think if you want monitor the connection, use the good old lifebeat. By the way your HMI should trig a system alarm on com's loss. Cheers
	- What you read here, please check with manuals and your requirements. - Do not forget to Test, Test and Test... - If the post is helpful, please RATE it! MicroMan
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8/25/2014 3:26 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 11/20/2019 Posts: 8266 Rating: (1395)	Karl84 Hi, Is there a specific OB or block which deals with a HMI loss. Previously I have experienced comms loss with Profibus using OB blocks but if you remove an HMI, no errors seem to occur. Cheers If you must have the hmi connected for proper operation and monitoring of your process, then you should look into configuring the portal hmi connection and "area coordination" details. From the area coordination, you can detect an hmi is online or not. Then your plc project can take appropriate action if the hmi is offline.
	science guy
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This contribution was helpful to 2 thankful Users MicroMan Diniz_

8/25/2014 6:16 PM	Rate (0)
Karl84 Advanced Member Joined: 8/28/2012 Last visit: 4/14/2019 Posts: 33 Rating: (0)	Cheers gents for your help, Looking at the Coordination, simply use a Word and read the 2 bit for the "Life Bit" which inverts about ever second to let you know there is a link between the CPU and HMI.

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8/25/2014 7:08 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 11/20/2019 Posts: 8266 Rating: (1395)	Karl84 Cheers gents for your help, Looking at the Coordination, simply use a Word and read the 2 bit for the "Life Bit" which inverts about ever second to let you know there is a link between the CPU and HMI. Does this mean your problem has been solved?
	science guy
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8/25/2014 7:51 PM	Rate (0)
Karl84 Advanced Member Joined: 8/28/2012 Last visit: 4/14/2019 Posts: 33 Rating: (0)	I haven't checked it as yet, but I'm pretty sure it will be ok. I did notice that on TiA Portal V13, that in the Advanced settings of the CPU you can get it to call OB82 if there is a comms fault (haven't checked if this applies to HMI comms).

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8/26/2014 3:49 PM	Rate (0)
Karl84 Advanced Member Joined: 8/28/2012 Last visit: 4/14/2019 Posts: 33 Rating: (0)	Yep the life bit works fine, thanks again gents. [snip] ...
	Last edited by: CS Moderator at: 8/30/2014 11:20 AM follow up question is split to a seperate thread with the subject /tf/WW/en/Posts/113711#top Last edited by: Karl84 at: 8/26/2014 5:28 PM
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1/29/2018 11:46 AM	Rate (0)
Jen_Moderator Moderator Joined: 6/19/2017 Last visit: 11/21/2019 Posts: 3653 Rating: (43)	New question published by ANSHUMAN_SINGH is split to a separate thread with the subject Generate a communication fault in HMI & in Wincc 7.4. Best regards Jen_Moderator

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