TheAlarmTech.com

hi...i'm new in est3

i have a problem regarding on the network est3..based on datasheet and previous statement have state the wire
length between 3 panel is 1500 meter.how about the forth panel because i have connect three panel
and it able to communicate , if i connect the forth panel,the voltage drop and the led at tx2, rx2 sometimes steady and
sometimes off.could somebody help me regarding on this problem and why this problem happen

com problems are usually a capacitance problem not a voltage drop problem, not saying it's not.
but check the capacitance first, the EST3 can run at 3 bauds 9600,19.2k or 38k, the slower the speed the less capacitance is a problem.
Which baud is your network running? do a download at 9600 see if it works, try 38k see if it fails.

I tried downloading a large system at 38k which runs on 19.2k and it locked up a panel ( I needed to plug into and download to unlock)

there is a post with a doc from EST about checking the RS-485 network line with a oscilloscope.