Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

Wire broken, under rang and over range informations

Created by: Alain Crettaz at: 8/30/2010 12:02 PM (4 Replies)

Rating (0)

Thanks 1

5 Entries

8/30/2010 12:02 PM	Rate (0)
Alain Crettaz Posts: 5 Rating: (0)	Good morning, I would like to get some information from analog card SM331 (AI8x12bit - 331-7KF02-2AB0). I work with 4 to 20mA (TM2F) 1 - I want to get on each channel separately, the information "wire broken". 2 - I also want to get the values "over range" (+ 20 mA) and "under range" (- 4mA). I search a bit on the side of the OB82 and OB40, but I'm not sure I understand their exact function. Also, I absolutely have these 3 information for each analog channel (8 temperatures or pressures per card, with control of such information for security.) Can you help me to recover this information? How should I parameter the analog card in HWConfig? Thank you in advance for your help Alain
Alain Crettaz Posts: 5 Rating: (0)	Last edited by: Alain Crettaz at: 8/30/2010 12:06 PM
Suggestion To thank Quote Answer

8/30/2010 2:45 PM	Rate (0)
dchartier Grandmaster-Expert Joined: 9/27/2006 Last visit: 11/7/2024 Posts: 12293 Rating: (2691)	Hello Alain; The module you are using does not allow hardware interrupts on all channels, unfortunately. However, there is an easy way to retrieve such information fromm all channels, by looking up the analog channel values. Simply compare the decimal content of each channel (PIWxxx) with the values in the left column of the attached document. If the value is between decimals 0 and 27648, you are in the rated range (4-20 mA in your case). If the value is above 27648 but under 32511, you are in overrange. If the value is between -1 and -4864, you are underrange. Above 32512 and under -4865 you are in overflow or underflow (problem with the channel). Since you are using a 4-20 mA signal, a value of underflow will indicate a wire break. Of course you can scale the value to whatever engineering units you wish, using FC 105 (SCALE) from the TI-S7 conversion library for example. But use the straight evaluation of the analog numeric value to get the information on the signal quality. Hope this helps, Daniel Chartier Attachment 4_20mA rep S7-300.JPG (440 Downloads)
	Last edited by: dchartier at: 8/30/2010 2:47 PM
Suggestion To thank Quote Answer

8/31/2010 10:09 AM	Rate (0)
Alain Crettaz Posts: 5 Rating: (0)	Thank you very much for your answer, it helps me. Just one more question : Where did you find the attachment? Is there also for the 0-10V? The values are the same for 4-20mA and 0-10V? Thank you for your help!
Alain Crettaz Posts: 5 Rating: (0)
Suggestion To thank Quote Answer

8/31/2010 11:28 AM	Rate (0)
Hulzhex Gold Member Joined: 8/25/2005 Last visit: 10/5/2024 Posts: 1162 Rating: (111)	Hello Alain Crettaz, think you will find the information you are looking for within the following manual: SIMATIC S7-300 S7-300 Module data Best regards Sabine

Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users dchartier

9/2/2010 8:07 AM	Rate (0)
Aret Posts: 2348 Rating: (264)	I agree with Sabine - you can use SFC51 or SFC59 to get wirebreaks under- and overrange. But please mention 2 things: 1) Diagnostic interrupt on module in HWKonfig should be enabled and 2) Channels are configured in groups of 2 channels - so you can't catch the difference between wirebreak on channel0 and channel1 for example - and that also means if you use only 1 channel in pair you should but resistor on unused channel
Aret Posts: 2348 Rating: (264)
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on