EG25G - Timeout for STATUS pin to go low and UART to become ready

IoT Modules LTE Standard Module
1

Hello,

I am trying to develop a robust system with the EG25G module and an external applications processor. I wanted to look at edge cases and what needs to be done if the module does not behave normally due to some unknown reason during operation in the field, to diagnose the problem on the go and to take corrective actions.

In this regard, I have the following questions related to the initialization of the EG25G module running the standard firmware with which it is normally shipped.

  1. The Hardware Design document (v1.3), Fig. 12 on page 40, shows that it would take >= 2.5s for the STATUS pin to go low after the PWRKEY pin is driven low. What should be done if the STATUS pin does not got low? What is the recommended timeout (upper limit) for the STATUS pin to go low?

  2. What does the RDY message (that is sent out on the UART interface by the module) really mean? Does it simply mean that the UART interface is ready to receive AT commands?
    What is the maximum timeout period for this RDY message to be generated by the module? The same figure (Fig. 12) indicates only the lower limit (12s).
    What is the recommended way to handle such a timeout? Should the power supply be cut? Or the PWRKEY be toggled again?

Thank you.

/patrik

2

Hello patrik, thanks for your question

  1. The initial boot process of the standard firmware has been set inside the module and cannot be modified. Under normal conditions, the STATUS pin becomes low level after 2.5s. If the timeout occurs, it indicates that the module has started abnormally, and it is recommended to power on again.
  2. The RDY message represents that the UART port can receive AT commands. Under normal circumstances, RDY messages can be received after 12s. If there is no RDY report, it is recommended to power off and restart.
    Thank you.