Skip to Content

Register Login

Default Header

(header konnte nicht geladen werden)

Navigation

Scan time problem

Created by: Nithin at: 9/19/2009 9:15 AM (2 Replies)

Rating (0)

Thanks 0

3 Entries

9/19/2009 9:15 AM	Rate (0)
Nithin Posts: 48 Rating: (0)	Hello, Last week i solved my channel redundancy problem, But I now have one question. In Modular redundancy i had an overall scantime of around 30 ms. But when we introduced Channel redundancy it went upto 50ms. The problem is that we should have a scantime less in the range of 25ms. We are using two 414H in Redundant mode, with around 250 AIs , 20 AOs , 500 DOs and .800 DIs. Is there any way to reduce the scantime .I mean can we avoid allocation of memory to unwanted priority classes in CPU prooperties. Is there a way to trim the scan time? Thanks Nithin
Nithin Posts: 48 Rating: (0)
Suggestion To thank Quote Answer

9/19/2009 9:18 AM	Rate (0)
Nithin Posts: 48 Rating: (0)	Can updating Firmware help them? We use IW addresses. ie, Not PIW addresses. Can allocating inputs to Part Process Images reduce scantime? Nithin
Nithin Posts: 48 Rating: (0)
Suggestion To thank Quote Answer

9/24/2009 1:01 PM	Rate (0)
sfa Posts: 70 Rating: (3)	Nithin Can updating Firmware help them? We use IW addresses. ie, Not PIW addresses. Can allocating inputs to Part Process Images reduce scantime? Nithin Hi Nithin My expirience tells me that if you have a preformance requirement for a plant where you normally would use an 414-3DP you will need the 417H in a redundant solution. But to go there now for you is quite costly I suppose :-) In a H system the use of L PIW will initialise a sync event between the CPU's, so to avoid that it's better to keep the L IW setup. But you should evaluate the update time for the IO and have it updated by interrupts (e.g. OB34 20ms) with an assigned Part Image Partion (PIP). PIP is assigned to the network nodes in the hw configuration manager. Another time consumer is communication, place your communication calls in e.g. 100ms interrupts and only call the block when you are sure the job is finished. every call will also trigger an sync event. Hope this can make you find a way to lower the scantime of your application /søren
sfa Posts: 70 Rating: (3)
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on