Er: <type, Syntax, Defined values – Comtrol AT Commands User Manual
Page 94: Example

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
Conexant
102184B
3-68
+ER: <type>
The +ER: <type> reported represents the current (negotiated or renegotiated) modem-
modem error control type. If enabled, the intermediate result code is transmitted at the
point during error control negotiation (handshaking) at which the modem has determined
which error control protocol will be used (if any), before the final result code (e.g.,
CONNECT) is transmitted. The format of this result code is:
The +ER intermediate result code, if enabled, is issued after the Modulation report
(+MCR and +MRR) and before the Data Compression Report (+DR).
Syntax
+ER: <type>
Defined Values
<type>
An alphanumeric code corresponding to the selected protocol.
NONE Error control is not in use.
LAPM V.42 LAPM protocol is in use.
ALT
MNP is in use.
Example
+ER: LAPM