AT Command Manual
v1.5
©2013 LM Technologies Ltd
www.lm-technologies.com
Page 11 of 26
2.8.11.2
AT+MODEM?<cr>
2.8.11.2.1
Response
<cr,lf>MODEMc<command_response> if the command is successful. Here, c- current
modem signal setting. E.g on default setup, the response will be <cr,lf>MODEM-
<command_response>
2.8.11.3
Modem Signal Meaning
The modem signal setting is used in conjunction with AT+FLOW Settings to enable/disable
RS232 modem control signals as per the table below.
FLOW
CONTROL
(AT+FLOW)
MODEM
SIGNAL
(AT+MODEM)
RS232 SIGNALS
USED
Description
FLOW-
MODEM-
Tx, Rx, GND
3 wire configuration.
FLOW+
MODEM-
Tx, Rx, GND, RTS,
CTS
RTS/CTS signals are used for data
flow control between host and
local Bluetooth device, and
NOT
transferred to remote Bluetooth
device wirelessly.
FLOW-
MODEML
Tx, Rx, GND, RTS<-
>CTS, DTR<->DSR
RTS looped back to CTS, DTR
looped back to DSR. No RS232
control signal transferred to
remote Bluetooth device
wirelessly.
FLOW+
MODEML
Tx, Rx, GND, RTS,
CTS, DTR<->DSR
RTS/CTS signals used for data
flow control between host and
local Bluetooth device, and
NOT
transferred to remote Bluetooth
device wirelessly. DTR looped
back to DSR.
This configuration is
equivalent to LM048 adapter
running v4.5x
firmware.
FLOW-
MODEMR
Tx, Rx, GND, RTS(R),
CTS(R), DTR(R),
DSR(R)
All 7 signals used. All RS232
control signals (DTR, DSR, RTS
and CTS) transferred wirelessly to
remote Bluetooth device.
FLOW+
MODEMR
Tx, Rx, GND, RTS,
CTS, DTR(R), DSR(R)
All 7 lines used. Only DTR, DSR
signals transferred wirelessly to
remote Bluetooth device.
If RTS,
CTS signals are not used, then
this configuration is equivalent
to LM048SPA Adapter running
v4.6X firmware.