Prabhakarankft
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You noticed that the power cable "influences" the signals on the data cable.Shield of Core cable is not connected anywhere and total length of the Cable is 4.4 Meter
Sure I will update the result after grounding the Shields! It it is happening randomly it will take time!Connect the shield at one end - possibly both
Receiving this 3.3V Signals through optocouplers(PC817 with 100E Resistor on Anode) will improve results?? Yet now I have not received any problems on this area..The threshold at which its logic level could be seen wrongly is only about 1.5V which is too small for comfort
Current consumption of Tx PCB is just 400mA( Tx getting power from Rx PCB). My Idea is 14/36 wire will be sufficient to carry this current! Among 5 Cables 2 is dedicated for Power (15V and Gnd)But without shields connected ... how is your idea.. how can it carry current?
Shall Use these parts on Tx??* use standard ESD protection diodes and a series resistor at the transmitter
* use an RC and ESD protection at the receiver
Being slow is not an issue for my application! This pin is used to just Identify the rotation of a Motor usually runs at 100 to 400 RPM. I need to find out exactly where the problem is ! If this will not be a cause, I will probe into some other area!the optocoupler is slow, thus it can´t transmit erroneous pulse signals
* the optocoupler LED is more rugged than a microcontroller input. Thus a medium energy pulse does not hurt the optocoupler
Connect the shield at one end - possibly both. You don't gain anything by have a floating shield and its close proximity to the 5 wires may increase interference coupling in to them.
Where to connect the shield! GND or Earth!! Which one will be wise option!
Hello,Hi,
ESD is low energy but high voltage.
But your suppressor diodes ar for high energy. Datasheet says: Power supply protection. But you need "signal line protection".
Additionally the 15V..17V rated voltage is too high. The clamping voltage will easily be above 20V....but you want protect a 3V3 microcontroller port. Dedending on what microcontroller you use... id´limit the current to less than 50mA peak.
50mA on a 100R means 5V. 5V above 3V3 means you have to limit the voltage to +8.3V and -5V.
Often simple diodes like BAT54S are sufficient.
In detail it depends on your expected ESD pulse waveform.
The problem is: we can not know what you have to expect. Textile industry often suffers from relatively high energy (for an ESD pulse).
Klaus
Hi,But using a the correct diode is only half the way, you also need a suitable PCB layout and maybe additional devices, like capacitors.
Klaus
I expect: any good ESD protection semicinductor manufacturer provides application notes / design notes for this.It would be great, If there is any documentation related to PCB layout for ESD protections
Hello KlausST,Hi,
I expect: any good ESD protection semicinductor manufacturer provides application notes / design notes for this.
Some even have examples in the datasheets.
Klaus
Hello Everyone!But We faced some times MCU on Tx end as well Rx end has stopped working(Completely gone off)
This makes no sense to me.if anything received other than Start bit,
Yes you are so correct! What I meant by Start bit is SW code continue-sly expect one constant (Character $) as a start bit. If any data other than $ means SW consider as Noise!"recieve without start bit"
Yes this should be corrected from my side!! Thank you!Please use the phrase "start bit" only when you mean the UART_start_bit.
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