LE910Cx AT Commands Reference Guide
80502ST10950A Rev. 14 Page 295 of 1904 2022-03-04
3.2.4.9. AT&S - Data Set Ready (DSR) Control
Set DSR behavior on RS232
AT&S[<n>]
Set command controls the RS232 DSR pin behavior.
Parameter:
High when DATA mode connected
High when the modem device is ready to receive AT
command
If option 1 selected, then DSR tied High when the device receives
from the network the UMTS traffic channel indication.
In power saving mode the DSR pin always tied Low & USB_VBUS
pin always tied Low.
If parameter is omitted, the command has the same behavior of
AT&S0.
If option 1 or 2 active, DSR will not tie High in case of GSM voice
connection.