This error occurs if data is received and the receive buffer is attempted to be overwritten while data in the receive buffer is being read to the memory in the communication module. For example, when the transmission speed is high and communication data amount is large, the system processing (reading data form the receive buffer) is delayed and this error occurs. To prevent this error, reduce the data amount or extend the transmission interval. You can calculate the receive processing time of the general purpose communication module from the receive data amount. For details, refer to the How-to Guide 'Restrictions on General Purpose Communication Module (Full-duplex Communication) in MICREX-SX Series' (GE0158).