You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

PLC training tools sale

Reply
 
Thread Tools Display Modes
Old May 27th, 2005, 01:06 PM   #1
sanjay_snj
Member
United Arab Emirates

sanjay_snj is offline
 
Join Date: Jan 2004
Location: ABU DHABI
Posts: 36
Update Totalizer In Both Cpu

hi all !

can any one help me out !!!!!

i m using 2 nos. of 315-2DP cpu in a redundant configuration. actually i do not know it is hot redundant or any other redundancy. it is configured using cpu 315-2DP and IM360 & IM361. All the I/Ps (Rack No.1) and Outputs cards(Rack No.2) are redundant.When I put one cpu in stop, all outputs are getting off and the other cpu taking over the control in 25-30 secs.

The values are updating in TP170a operator panel also using cpu314 (called ALNAR1)

my prolem is when when one cpu is in line (called ALNAR 2), it is having one totalizer which is totalising the total flow value, read in one DB. When the cpu change over due to any problem, the totalizer value is not getting updated in another cpu (ALNAR3)and i am getting different totalizer value in both the cpu.

can any one help me out in keeping both the totalizer values synchronised .

thanx.

sanjay
  Reply With Quote
Old May 28th, 2005, 12:24 AM   #2
dchartier
Member
Canada

dchartier is offline
 
Join Date: May 2003
Posts: 1,539
Hello Sanjay;

Siemens offers a software Redundancy package for S7 CPus (it is the only option for redundancy for the S7-300 CPUs). This illustrates the basic principle:




Now, it appears from your description that you are not using this package and that you have some kind of homemade system checking switchover between CPUs, probably using a lifebeat signal to determine if the master CPU is actve.
At this time I have to say that synchronisation between the values read by each CPU do not seem to be controlled. We need details on how the information is exchanged between the CPUs in your system. Are all I/Os simply duplicated (hard-wired ) to each CPU? In that case, how do you make sure that the same data is read between the CPUs? Is there a network linking both CPUs? If so, you could transfer the totalizer value from the master CPU to the Stand-by over communication link (along with all pertinent data for switchover control);use the hard-wired info on the stand-by CPU only when it takes control. But if you are devising the system by yourself, you face a lot of data validation problems.
Please don't hesitate to come back to the foru\m with more details on your harware and software configurations. With more details, we can give more informed opinions.
Hope this helps,
Daniel Chartier
  Reply With Quote
Old May 29th, 2005, 02:15 AM   #3
Amr Hassan
Member
Egypt

Amr Hassan is offline
 
Join Date: May 2005
Posts: 340
To my knowledge u must use ET 200 M with a redundant bundle of IM153-2 to make sure that the inputs are accessed by both CPU's
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
AD 250-1 CPU How can I reset-erase this CPU so I can use it with a NEW program withou Anibal Hernandez LIVE PLC Questions And Answers 16 March 22nd, 2011 08:21 AM
Funny effects when uploading project to S7 300 CPU RMA LIVE PLC Questions And Answers 9 October 28th, 2004 07:44 AM
S7 CPU Parameterisation problems after loading program RMA LIVE PLC Questions And Answers 12 October 7th, 2004 09:12 AM
Changing from Melsec A3H CPU to A3A CPU Ptilou LIVE PLC Questions And Answers 3 October 2nd, 2003 05:56 AM
how often should I trigger the PID? Ron Beaufort LIVE PLC Questions And Answers 11 February 22nd, 2003 10:57 AM


All times are GMT -5. The time now is 04:56 AM.


.