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michel

A1SX81 speed-up

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Hi, The A1SX81 is a 32 point input module, the response time (on and off) is 10ms. I would like to get it down to 1ms. Has anyone ever tried opening the module and take some capacitors out? Or is there another way of doing so? Michel

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I only know of high speed input module. High speed input module can attain a response time of 1ms or less depend on whether is AC or DC. I hope it helps.

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i would not consider modifying plc hardware. removing or altering filters is only part of battle (and only works if filtering is done externaly). what is your current scan time? what exactly are you trying to acomplish?

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Hi, I made a dual sensor for a cut-to-size wire straightener, the dual sensor measures the speed of the wire over a 12.5mm distance. A cut signal will be generated according to the speed of the wire. The cut signal has a variable delay, I put it into a formula that includes cut-time and wire speed. So if the cut-time is known and the speed of the wire is also known, the end result is wires that always have the same length (approx +/- 1mm over a 4.5m length). The speed of the wire varies between 0.5m/sec and 2.0m/sec. That leaves us with 6.25ms to 25ms between the 2 sensors that are 12.5mm apart. That's not a lot to work with, so the inputs have to be very quick. 0.1ms would be ideal. Michel

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looks like you don't need 32 fast inputs. where do you get product speed information from? normally this is what high speed cards are for. you wire encoder and any registration sensor into inputs of high speed counter card, then use code to set number of pulses when the high speed output comes on (normally this is also part of the high speed counter card). this way you get pulse on output that corresponds to programmed product length and it works independent from scan time or product speed. i have done this on other (not Mitsubishi controllers) but they all should work the same way. i'd definitely look into functionality of the high speed cards.

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Hi, yes, that's right but I am talking about 2 different applications. For 1 I need at least 12 high speed inputs, the other only 2, or actually 4 because I want to connect 2 sensors to it. The product speed I calculate by use of the 2 sensors that are 12.5mm apart. I measure the time difference between detection on sensor 1 and sensor 2, then 12.5mm divided by the measured time gives me the product speed. At least, that's the idea. I did a bit of testing using a high speed ring counter (0.1ms increments), I clear the counter when 1st sensor is reached and let it count until second sensor is reached. That works well in theory, but the current PLC I am using is too slow to get it accurate, but that's a minor issue. I have 2 of these 32 point input units now eating dust, so I think I am going to the hardware modification anyways to see how that performs together with a Q2A. If that works fine, I am thinking of an FX3UC as they seem to match the performance of the Q2ASHcpu-S1 quite well. Any idea? Michel

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1ms inputs in an A1S family might not be available. In the Q Series, you can cut the response time on a card by card basis in PLC parameters all the way down to 1ms. Consider interrupt input cards?

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