How to recieve analog input faster.

    Hello,

    So i have this cell where I have to check how much tape is present on my taping head.

    The thing is that when I was testing the Analog input the time from min to max value is around 35 seconds which is terribly slow near the minimal and maximal values (0-1441).

    When I measured this with multimeter the values went much much quicker which made me think that Fanuc is slowing it down for some reason, maybe it's a software thing.

    So I'd like to know If there is a way to somehow speed up this process, maybe changing a variable of some sort.

    Hope this makes sense, I'm in a bit of a rush. Any tips are appreciated :winking_face:

    :wheelchair_symbol: Still learning please be patient :wheelchair_symbol:

    Hey thanks for the reply,

    We are measuring voltage.

    So I have this horizontal rack with an I/F card which is connected to the R30iB Compact Plus and 2 analog input cards on this rack right next to each other (both 12bit).

    Yeah its quite slow which really wouldn't be a problem in itself, but the time to change the tape on my taping head is around 1:30min and I can't really have 35s just to measure the tape.

    :wheelchair_symbol: Still learning please be patient :wheelchair_symbol:

    Quote from Bapp

    The thing is that when I was testing the Analog input the time from min to max value is around 35 seconds which is terribly slow near the minimal and maximal values (0-1441).

    Nation is right, that's insanely slow. How are you changing the voltage input? Just pushing the sensor to one limit, then throwing it to the other limit? How fast is the sensor physically changing between max and min?

    Quote from Bapp

    So I have this horizontal rack with an I/F card which is connected to the R30iB Compact Plus and 2 analog input cards on this rack right next to each other (both 12bit).

    So, IIRC, the Fanuc should communicate with the analog input device every 12ms. So I'm inclined to think the issue is somewhere in the I/F card. It sounds almost as if your AD converter has some sort of rate limit (maybe a hefty low-pass filter?), or possibly a big capacitor (which has similar low-pass filtering effects, but in hardware) on the analog side. Given what you're seeing with a voltmeter, I would doubt the capacitor, but it'd still be something to check. Ideally you could capture the voltage waveform over time with a o-scope or a DAQ and see the shape of the voltage/time curve.

    I don't know offhand if Fanuc has any built-in low-pass-filtering available in the software config of analog inputs, but that would be something to check for. How are you monitoring the input on the robot side?

    Quote from SkyeFire

    Nation is right, that's insanely slow. How are you changing the voltage input? Just pushing the sensor to one limit, then throwing it to the other limit? How fast is the sensor physically changing between max and min?

    We used a linear potentiometer just to test the card out. Yeah so we pushed it to either limit and just waited to see how fast and far the value in AI [1] gets. Physically the sensor is quite fast, just push or pull takes about second to do it maybe less.

    Quote from SkyeFire

    So, IIRC, the Fanuc should communicate with the analog input device every 12ms. So I'm inclined to think the issue is somewhere in the I/F card. It sounds almost as if your AD converter has some sort of rate limit (maybe a hefty low-pass filter?), or possibly a big capacitor (which has similar low-pass filtering effects, but in hardware) on the analog side. Given what you're seeing with a voltmeter, I would doubt the capacitor, but it'd still be something to check. Ideally you could capture the voltage waveform over time with a o-scope or a DAQ and see the shape of the voltage/time curve.

    It's our first time working with analog cards and basically with FANUC in general. We dont really have an o-scope to check, worst case scenario is we will just run the sensor throught PLC which has proven to work before.

    Quote from SkyeFire

    I don't know offhand if Fanuc has any built-in low-pass-filtering available in the software config of analog inputs, but that would be something to check for. How are you monitoring the input on the robot side?

    Yeah so I'm still searching for some variables or some config I could use and tweak to have desired outcome. We are monitoring the input from the AI [1].

    :wheelchair_symbol: Still learning please be patient :wheelchair_symbol:

    • New

    Hm... there's a thread from a few years back with a similar issue, but no resolution:

    Thread

    AAD04A Analog Input Card Refresh Rate

    I am having an interesting issue where the analog input is updating extremely slowly. I have a laser sensor that outputs 0-10V, this signal wire is landed on V+, the V- has the same ground that the sensor is using and com and v- are connected.

    I can see on the multimeter the sensor output switch from 0 -> 10V instantly but on the card it's updating at about 35/sec (0-600, respective to my 0-10V).

    Anyone have any idea why my refresh rate would be so slow?

    It's on a R30iB controller.
    KyleW
    February 2, 2021 at 2:35 PM

    So you're not the only one.

    There's another one that has a different problem, but the discussion might be useful:

    Thread

    Analog Input Wiring

    Hello all

    working with an R30IA Controller.

    I got a AAD04B Analog input module and I would like to connect a Balluff Distance Sensor to it. I am new to analog signals and am confused how to connect the sensor to the input module.

    attached is a picture of the Fanuc module schematic and a picture of the Balluff sensor schematic.

    Any Help is much appreciated. thanks.

    robot-forum.com/attachment/35646/ robot-forum.com/attachment/35645/
    jariuscs
    October 5, 2022 at 12:42 AM
    • New

    So still not really a solution, but maybe someone will find this useful.

    I tried changing $SCAN_TIME variable to 1 (ms) and it sort of helped with the refresh rate of the values gained from analog input. Right now it is somewhat acceptable for my application.

    :wheelchair_symbol: Still learning please be patient :wheelchair_symbol:

    • New
    Quote from Bapp

    So still not really a solution, but maybe someone will find this useful.

    I tried changing $SCAN_TIME variable to 1 (ms) and it sort of helped with the refresh rate of the values gained from analog input. Right now it is somewhat acceptable for my application.

    Have you tried this ?

    39412-pasted-from-clipboard-png
    • New

    Well I did sort of.

    I picked IOLNK[1] and put in the same rack and slot as my analog input card was mapped to:

    Rack= 1 Slot= 1 Input_n= ? Output_n= ? Option= 1 - dont really know what IN/OUTput_n is.

    All it did was change the values of the card from +-4086 to +-65656 so yeah I kind of just went with the scan time

    :wheelchair_symbol: Still learning please be patient :wheelchair_symbol:

    Edited once, last by Bapp (June 11, 2025 at 8:04 AM).

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