First you need to know if PICAXE microcontroller has a predefined set of communication protocol (i.e. it expect certain incoming command format and will respond in a certain format). If it does have a communication protocol and if it is non-standard protocol then you will need to use TBASIC to write a formatted string and send it out of RS485, then expect a certain return string from PICAXE. One example you can follow is using the T100MD+ PLC with the I-70xx analog module. This is produced by a third party and it has its own simple ASCII command protocol. We provide sample programs showing how to use TBASIC NETCMD$ command to write the custom protocol to the I-70xx and get a return string and how to interpret the response string. You can find examples in your "samples\I-7000" folder in your i-TRiLOGI installation.
If PICAXE does not have a communication protocol, then you will have to design and implement a protocol in the PICAXE using some low level routine. In this case you have the freedom to design your own protocol and this is beyond the scope of this support forum.
