Mesut_yigit
Newbie level 5
Hi friends;
I have 30 pic boards connected to a PC. Communication system is based on 4 wire RS 422 system. Biasing of comms line is performed using two 470 ohms to GND and + 5volt lines. Also , lines are terminated at each end. Line drivers are SN75176.
Strange thing is , when I start communications , PIC is resetting , exactly at the same point of communication. Even if I remove the comms cable , problem is still exist. Without the cable plugged, system becoming more sensitive against noise. Even when I try to touch to system , the LED s that are connected to Tx and RX lines (C6 and C7 pins) are lit.
I cancelled watch dog , Stack Underflow /overflow reset , Brownout ETC. But nothings changed. I am suspecting the noise. System is working in an industrial plant. I have used CAT 5 cable as comms. cable.
Could someone help me ?
I have 30 pic boards connected to a PC. Communication system is based on 4 wire RS 422 system. Biasing of comms line is performed using two 470 ohms to GND and + 5volt lines. Also , lines are terminated at each end. Line drivers are SN75176.
Strange thing is , when I start communications , PIC is resetting , exactly at the same point of communication. Even if I remove the comms cable , problem is still exist. Without the cable plugged, system becoming more sensitive against noise. Even when I try to touch to system , the LED s that are connected to Tx and RX lines (C6 and C7 pins) are lit.
I cancelled watch dog , Stack Underflow /overflow reset , Brownout ETC. But nothings changed. I am suspecting the noise. System is working in an industrial plant. I have used CAT 5 cable as comms. cable.
Could someone help me ?