RV50 modbus communication trouble

I have a setup of 5 RV50 units setup for modbus communication protocol. These were all working fine until one day I noticed my PLC had communication failure for each site. I ended up replacing the RV50 master and communications returned but now with only a 50% success rate. Since then I have tried a new antenna at both the master and a remote site, different antenna cable, new modbus serial cable and different serial port on my PLC. Despite this only 50% of my modbus messages go through. I am only asking for 16bits of data from each of 4 remote units once a minute. Any help would be appreciated. I am starting to wonder if Verizon messed something up but I have the green strong signal light at each location. I attached a copy of my remote and master files.
Cell_files.zip (26.3 KB)

Hi @Matt1,

I notice that you are using the outdated ALEOS 4.9.2 for RV50. Please try updating to the latest ALEOS firmware to see if it resolves the issue.
Here is the link to the latest firmware: https://source.sierrawireless.com/resources/airlink/software_downloads/rv50/rv50-firmware-list/
Additionally, if possible, please share the log file from the RV50 with me.


Ok, I will give that a try and report back.