The Trio firmware can open a Modbus Client port and communicate with any Modbus Server. Port number is usually 502. You need to have the document from the slave vendor that lists the register numbers in the Modbus connection of the device. Probably they will be Holding Registers numbers either 0 to 9998 or 40001 to 49999.
The open command is like this.
MODBUS(open_modbus, mb_slot, 192, 168, 0, 250, 502, mb_handle, 3)
Look at the examples in the MODBUS command in Trio BASIC Help.
Note a Modbus Server in the Trio Motion Coordinator does NOT use the MODBUS command, only the client uses it.