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7/1/2009 10:36 AM | |
Joined: 10/7/2005 Last visit: 9/23/2024 Posts: 3022 Rating: (1054) |
Hello Georgi just for your peace of mind, I agree with comments made by others and you can rest assured that the 317 will have no problemswith the amount of AI's that you have. Having said that and assuming you somehow manage to write some really runtime heavy, hideous amount of PLC logic (which I'm sure you won't) and manges to endup with a cycle time of let's say 150ms, you still needn't worry about your AI's. Why is this you ask?, well the answer is simple, the 7KF02 AI card that you picked (which is one of the most versatile and hence most commonly used ones)needs at least 22ms per Analogue Input conversion (if you set it up for 50Hz supression which is what I would do). To do the A/D conversion for all channels, the card needs (as a bare minium) 176ms all up so even a cycle time of 150ms won't affect the "speediness" of your AI reads. You'll find the above and more info about the I/O cards in this S7 300 module datamanual. The "vendor" who recommended to use an S7-400 instead obviously "overlooked" to take this into account (or was tryingto sell you High Speed AI too) Good luck with your project |
Cheers |
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