Hello @anas2662,
First, I should say that if you are looking for help getting your radios working right away, this is really not the best place to ask your questions. Instead you can contact our Technical Support team:
SupportTRSS@se.com or
1-888-226-6876
I can respond generally though. Certainly, the Trio QR450 radio can replace Trio ER450 (two serial ports) or ER45e (one serial, one ethernet) radios, when configured for the E/M Compatibility mode. As you're trying to set up two serial ports you would need to configure both serial ports of the radio, after it's been changed to E/M Compatibility mode.
You must ensure that the Port stream ID's match at both ends of the link, and that they are different between the two ports. For example, Port A could use SID 3 for both Rx and Tx, and Port B can use SID 5 for both Rx and Tx.
If you use different SID's for Rx and Tx, they must be reversed at the distant radios. Different Rx/Tx SID's is not necessary except for unusual cases, but if you are doing that, typically it would be something like:
Port A Master Radio: Rx = 3, Tx = 4 Remote radios: Rx = 4, Tx = 3
Port B Master Radio: Rx = 5, Tx = 6 Remote radios: Rx = 6, Tx = 5
Typically Carrier Detect collision avoidance mode does a pretty good job to minimize collisions. Ensure that is enabled in all radios. Also, the E Series radios (or Q series acting as E Series) has a transmit data buffer for each serial port, and will only allow one port to access the radio channel at a time. However, if two remote device at different sites both decide to transmit at the same time there is not much that Carrier Detect collision avoidance can do about that. (especially if those two sites cannot hear each other)
Also, of course, the serial port settings must match in the radio and devices connected to each port of the radio. And the serial cables should be standard 3-wire straight-through type.
Again, I do suggest you contact our Tech Support team for any further assistance with this issue.
Joel Weder
Remote Operations Specialist
Schneider Electric