Need help with cnReach serial to serial application

Got two single 900Mhz ISM connected and an Emerson ROC at each side. We have set up serial settings at the slave ROC as "terminal server" so that the radio would request MODBUS registers and the master ROC is connected to the radio set up as the "client terminal". Both are running RS232:19200:8:1:NONE:NONE and the radios are showing packets TX and RX but there is no communication between the ROCs. Master ROC polls IP of the slave ROC radio with port set up to typical 502.


We have tried using RS485, different baud rates, different serial connection such as UDP Terminal, tried RS485 to RS232 via radio configurations, changed ROC configurations to go Ethernet MODBUS TCP/IP from Master to RS232 Slave and still no responses from the Slave.

Currently, set up as RS232 both sides, Client/Server serial settings and Slave ROC has RX lights but no TX. Anyone know if radio will not do MODBUS serial to serial and if it need to be strickly TCP/IP? Our restraint is that the Slave ROC is customer owned and will not go ethernet.

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Hi Dos,

In your setup, it looks like the proper configuration should be RADIO1-AP as Terminal Server and RADIO2-EP as Terminal client, so the radio link will carry RS232-over-IP for your ROC communication.

Please try it out and let me know.

If it still does not work, please email me and I will help you over the phone.




Solution was to update firmware and set up as UDP terminal with ports set to each other. After that RS232 comms were established. We are running multiple radios to one AP now. Thanks for all the support.

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Glad to see you up and running!  Can you provide a little background on the use case/application that you are utilizing the cnReach set-up in?  How is performance now that you are up and running?  Scott

The location is remote, and is upstream oil. We are using the cnReach to communicate between different sites owned by different clients. All the information gatherered goes to one Master ROC. We have one AP set up to poll over the radio UDP terminal set up to serial port 1. The AP radio has port 4100 set, and slaves are set to 4101. The modbus gets polled per address and we can get any information we want via the radios. The performance of the setup is very reliable and we will use this setup for future job sites.

An update on our system settings. We are using the newest serial setup for the cnReach and we have the current setup as follows:

AP- Seamless Serial; port setting; TCP Client to serial port of our choice

Slaves- Seamless Serial; port setting same as AP; TCP Client to serial port 1

The Seamless Serial is currently deployed at one of our sites. Cambium has been very helpful with the setup and deployment.

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