I wanted to get some direct debug logging. It took me some time to figure out the diag port only echoes what is sent from the SIM908 to the PIC18, I first thought it tapped RX+TX so I could see the complete communication. Next problem was the modem switches echos off (after COPS I think), so I need to re-enable them at least once in a while. I'm now using this scheme in can_state_ticker1(): #ifdef OVMS_DEBUG // CAN debug log via DIAG port SIM908 command echo: // ATT: could be a problem for running data transfers, // should not be enabled for production/live firmware images! net_puts_rom( "ATE1\r" ); sprintf( net_scratchpad, (rom far char*) "# ERR=%u SOC=%u RNG=%u SPD=%d PWR=%d CHG=%u\r", RXERRCNT, can_soc, can_range, can_speed, can_power, car_chargestate ); net_puts_ram( net_scratchpad ); #endif My questions: am I right with the suspected problem, and is there a better way? Regards, Michael -- Michael Balzer * Paradestr. 8 * D-42107 Wuppertal Fon 0202 / 272 2201 * Handy 0176 / 206 989 26