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khecimovich

RSLogix 5000 Running Slow

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I am running RSLogix v19 on my HP laptop (Windows XP on one HP PC and Windows 7 on another HP PC). I am experiencing difficulties going online with a 1756-L63 processor. My scan times are around 50-60ms and my Estimated Data & Logic Memory is around 25% used. Therefore, I'm not bogging down my system due to low memory. I am connecting to this PLC through a plant network. On this network is 4 AB HMI's, 10 SMC remote IP devices and two computers. I have already verified that my Rockwell Application Services are setup as Automatic and Running. Any hints or suggestions are very welcome.

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Which ethernet card are you using. The ENBT has a limited number of connections. Are you going through the router or are you "inside" of the router (meaning connected downstream).

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1756-A7 Chassis 1756-L63 1756-EN2T (Slot #2) 1756-EN2T (Slot #3) I am going through a un-managed switch to connect these devices.

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You can overload your processor if you are not careful with your periodic tasks. I have played with the task settings and you can overwhelm the processor so that it will not communicate at all if you set a periodic task too fast. Dont let the system overhead slice % fool you. The tasks take precedence. I would suggest using the task monitor tool to look at your various programs to get a better idea how fast they are running and what percentage of that time is actually used. If you have a 50 ms periodic task that takes 30 ms to run then not much time is left over for other functions.

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I have seen communications between RSLogix5000 and the controller seriously impeded when any one of the I/O modules RPI setting is set "very fast"... Some modules RPI can be set for 0.2 mS (200 uS), and when someone did it, we got very poor response in RSLogix5000 update times.

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I first verified that I do not have any I/O modules that are running "Very Fast" nothing is quicker than 10ms. I verified that any I/O modules that were not being used currently, were also inhibited. I have attached two images of the Task Monitor tool. Any other suggestions are very welcome at this point.

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I just updated my SOTS (System Overhead Time Slice) from 20% to 40%. That seemed to definitely help, but my average scan time increased by 10ms (+/- a few ms). With the amount of available memory that is available on this processor we are planning on adding much more to our plant on this PLC. Did I basically just mask the main cause of this problem or is a 40% SOTS typical for a L63? Thanks

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Your Task monitor showed a SOTS of 30% and it looks like it is using every bit of it. For me, 20-30% is typical. I dont really understand why your CPU is getting hit so hard. The task monitor indicates that the continuous task is using all of the available CPU time, but my continuous tasks dont seem to use the processor up that much. Granted I am looking at a 73 on my desk connected to nothing but Logix and a SCADA system. Your periodic tasks dont look to be overly aggressive according to the percentage shown, and you set your priorities different which is good. I can can only estimate what your periodic tasks are set for and they look really fast. Do they need to be that fast or can you slow them down a little to see if that affects your continuous task speed and your CPU utilization?

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