Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

When Digital input signal is unavailable

Created by: Donehill at: 6/6/2009 10:31 AM (13 Replies)

Rating (0)

Thanks 0

Result pages:: |; 1 | 2; |

14 Entries

Entries per page: 10 | all

6/6/2009 10:31 AM	Rate (0)
Donehill Posts: 64 Rating: (0)	Hi, How does WinCC 7.0 differentiate whether a digital input has been disconnected? By obtaining signal from a digital input, I can only get true (1) or false (0). If the digital input is disconnected, by default it will return to false (0). I need an alarm to be generated when theres no signal at the digital input.
Donehill Posts: 64 Rating: (0)
Suggestion To thank Quote Answer

6/6/2009 10:48 AM	Rate (0)
Ammy Platinum Member Joined: 4/19/2008 Last visit: 11/21/2024 Posts: 1525 Rating: (159)	Hi, To generate the Message on Negative in WinCC go to the Message properties in that click the Check box "is created on negative edge" by this setting when your signal goes to low that time it generate the message. Ammy
	Ammy New for every one.............. “No duty is more urgent than that of returning thanks.” If Problem Solved......! I can't help you privately - please post in the Forums
Suggestion To thank Quote Answer

6/6/2009 11:07 AM	Rate (0)
Donehill Posts: 64 Rating: (0)	Thanks for the help Ammy. What I meant was when there's no signal at digital input, for example like analog input, if theres no signal or connection, the object will be shaded. I need to do the same for digital input too, when i disconnected the PLC, my digital input should be shaded or something similiar. How do I generate an alarm if theres no signal at analog input?
Donehill Posts: 64 Rating: (0)
Suggestion To thank Quote Answer

6/6/2009 11:14 AM	Rate (0)
Ammy Platinum Member Joined: 4/19/2008 Last visit: 11/21/2024 Posts: 1525 Rating: (159)	Hi, for this you have to select the Diagnostic module in that you will get the wire brake detection, & to generate the Alarm you can used the Report System Error. Please tell me the which digital Module you are using ? Ammy
	Ammy New for every one.............. “No duty is more urgent than that of returning thanks.” If Problem Solved......! I can't help you privately - please post in the Forums
Suggestion To thank Quote Answer

6/6/2009 11:35 AM	Rate (0)
Donehill Posts: 64 Rating: (0)	Thanks for the help again, I'm using 6ES7 321-1BL00-0AA0 for digital input and 6ES7 331-1KF01-0AB0 for analog input. Where do I find the Diagnostic Module and the Report System Error? Sorry I'm still new to WinCC 7.0.
Donehill Posts: 64 Rating: (0)
Suggestion To thank Quote Answer

6/6/2009 11:53 AM	Rate (0)
Ammy Platinum Member Joined: 4/19/2008 Last visit: 11/21/2024 Posts: 1525 Rating: (159)	Hi, for given module it is not support the Diagnostic feature, 6ES7 -321-7BH01- 0AB0 is required. Or any interrupt module given in list, 6ES7-331-1KF01-0AB0 is also the basic module it also not support the Diagnostic feature, used 6ES7-331-7KF02-0AB0. For report system error search the report system error in the Search option on Siemens site. Report system error option is in the Hardware Configuration; right click on the Hardware configuration (in blank area) in that station properties-> settings -> click the save during “save & compile” Ammy
	Ammy New for every one.............. “No duty is more urgent than that of returning thanks.” If Problem Solved......! I can't help you privately - please post in the Forums
Suggestion To thank Quote Answer

6/6/2009 1:38 PM	Rate (0)
Donehill Posts: 64 Rating: (0)	I need to log a digital input status, when the status changes, the status is archive somewhere. For instance when a device is turn on, WinCC will save its status into an archive and when its off, the status will be save again. Do you have any idea on how am I suppose to do it? Thanks.
Donehill Posts: 64 Rating: (0)
Suggestion To thank Quote Answer

6/6/2009 2:05 PM	Rate (0)
Ayman Elotaify Platinum Member Joined: 5/28/2008 Last visit: 12/7/2024 Posts: 4516 Rating: (840)	Hello, 1. For understanding how RSE "Report system Error" Work and/ or how to implement it in your software, please read the following thread carefully: https://www.automation.siemens.com/WW/forum/guests/PostShow.aspx? PageIndex=1&PostID=144787&Language=en 2. I can not imagine how would you like to know if there is a wire break in a DI signal! Normally wire break could be detected for analogs. How it works? Suppose that you have 4-20mA analog input signal. So in normal operation, the analog input channel should recieve current between 4 & 20 mA. Then If this current falls bellow 4 mA? or become zero? Then you should think of a wire break has been happened. Thus exactlly how the wire break signal triggers. Now think in it for DI. The DI may be 1 or 0 in healthy condition, so it's impossible to monitor wire break!! Or if you want, you can pay for a security man to standup beside the wire of that DI. Regards,
	Last edited by: Ayman Elotaify at: 6/6/2009 2:09 PM Ayman Elotaify
Suggestion To thank Quote Answer

6/6/2009 2:20 PM	Rate (0)
Ammy Platinum Member Joined: 4/19/2008 Last visit: 11/21/2024 Posts: 1525 Rating: (159)	Dear Ayman Elotaify, Please checked the properties of the above DI module, in that you can find out the setting for the Wire breck, but till date I was also not used this module for wire brack but used for the Chanel Diganostics. for Archive of DI in WinCC go to the tag logging in that creat the new Archive Wizard in that you have to select the tags you have to archive (each DI tag must be created), then you can select the respective Tag properties in that rachiving TAB select Archiving Type - Acyclic, & acqisition - Event controlled & in Parameters select the which event you have to log into the system. then you can see the status by Calling the WInCC online Table control or WinCC Online Trend Control. Ammy
	Ammy New for every one.............. “No duty is more urgent than that of returning thanks.” If Problem Solved......! I can't help you privately - please post in the Forums
Suggestion To thank Quote Answer

6/6/2009 5:46 PM	Rate (0)
Ayman Elotaify Platinum Member Joined: 5/28/2008 Last visit: 12/7/2024 Posts: 4516 Rating: (840)	Dear Ammy, First of every thing look here for the technical specification of the DI module mentioned "6ES7 321-1BL00-0AA0". It's attached. The module inputs is normally "1" or "0" as it's a digital module. If the input signal become between 13V to 30V, the module will tell the CPU that high signal has been aquired. If the input signal become between -30V to 5V, the module will tell the CPU that low signal has been aquired. Thus from the technical specification. Now you have a connected module. ok? Cut a wire for one DI. Measure the voltage on the module channel. How much? It will ne zero. The module will understand it as a low signal "0" How should the module know that you have cutted the wire? That's the point. This case is completlly different for analog signals as I have mentioned in my last post. Regards, Attachment 6ES7 321-1BL00-0AA0.pdf (107 Downloads)
	Ayman Elotaify
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on