Posted 7 Oct 2022 This is not my build. I have a program that is using the P2-HSI to read counts from a quadrature encoder to display Feet Per Minute and Total Feet on an HMI. The displays do not work. When I look at the logic I see a MATH block that is assigned to Channel 1 POS, with the result to a tag, ENCODERS-IN_FEET. This tag is being read by the HMI using the same tag. There is no activity at the tag in data view. When I look at the Configuration of the HSI there is a set-up for CHANNEL 1, but there is no tag at Module Setup, 1A or 1B. Is there an instruction set, for the HSI, that would explain the proper set-up of the HSI module? The programmer is not available, he passed away during Covid. Share this post Link to post Share on other sites
Posted 7 Oct 2022 Hi Optinova, That config looks perfectly normal. There's no "instruction set" because this is a purely hardware counter. You only need tags assigned to Ch 1A and/or Ch 1B if you want to monitor the actual quadrature phases, which is only practical at very low speed. Since the counter is configured for Quadrature X4, you can check for a blown input by monitoring Channel1_Pos directly. If it blinks up and down by one count for any motion, then one of the two phase inputs is broken. The failure could be in the module, or it could be in the encoder that is driving the input phases. If you have this behavior, assigning temporary tags to Ch 1A and 1B for monitoring would help verify. If all else fails, get out an oscilloscope and see what waveforms you have on the inputs when the encoder is spinning. Phil Share this post Link to post Share on other sites
Posted 11 Oct 2022 Phil, Well, the scope revealed the encoder was bad. I replaced it and corrected the wiring to get the count direction right. Now I have an issue with another area. The encoder signal is also used to track Feet Per Minute. The function works, but intermittently, almost like a cycle, the display resets to zero and starts back up. I saw the 1B light get bright, for a second, every time this happened. I also see this in channel1_pos, it suddenly goes negative, then back to normal. I don't know if the module is bad, or the encoder is. I'm going to try connecting it to channel2 to see if the problem follows. Share this post Link to post Share on other sites
Posted 11 Oct 2022 You might have a partial short somewhere, or a ground loop, that is stressing the electronics. Might be what broke the previous encoder. Share this post Link to post Share on other sites
