Hello,
Module: EC200UCNAC-N05-SNNSA
Firmware: EC200UCNAAR03A03M08
I’m encountering a peculiar issue described below.
Initially, the device was on the network when the microcontroller was blank (no AT commands sent at all). However, when I load my code, which includes AT+CFUN 1,1, on power-up, the module resets and permanently loses the network. This issue is consistent across four boards, all exhibiting the same problem.
Interestingly, the same SIM card functions correctly on other EC200 modules (no code in MCU). Additionally, when I insert a new JIO SIM, the problematic module successfully detects the network after erasing the MCU code for testing.
There are no issues with Airtel SIM cards; my code performs as expected.
I am uncertain whether this problem is specific to JIO or EC200 module, as both combinations work when interchanged with another JIO SIM card or module.
This problem can be replicated. If I deactivate CFUN on the new device, the network functions as anticipated. However, if I enable CFUN commands during the device’s power-up, the device permanently loses network connectivity.
Command sequence on power up is as shown below.
“AT+CFUN=1,1\r\n”
“AT+CMGF=1\r\n”
“AT+QLTS=1\r\n”
“AT+CTZU=3\r\n”
“AT+CPIN?\r\n”
“AT+CSQ\r\n”
“AT+CCLK?\r\n”
Your assistance is appreciated.