Comtrol RM-4 - Manual (Page 7)

Hardware Installation and Specifications RocketModem IV: 2000468 Rev. A - 7
AT Commands
Hn Disconnect (hang up)
H0 Hang up (default).
H1 Go off-hook
In Modem Identification
I0 Reports product code (either 33600 or 56000).
I1 Reports 255 if the pre-stored checksum value is FFh
I2 Reports OK (for software compatibility).
I3 Reports the Firmware version of modem
Example: 3.xxx-V90_2M_DLS
Ln Speaker volume
L0 Off or low volume
L1 Low volume (default)
L2 Medium volume
L3 High volume
Mn Speaker control
M0 Speaker is always off.
M1 Speaker is on during call establishment, but goes off when carrier
is detected (default).
M2 Speaker is always on.
M3 Speaker is off during dialing and when receiving carrier, but on
during answering.
Qn Quiet results codes control
Q0 Enables result codes to the DTE (default).
Q1 Disables result codes to the DTE.
Sr Read or write to S-register “r”
r Establishes S-register “r” as the default register.
r= n Sets S-register “r” to the value “n”
r? Reports the value of S-register “r”.
Vn Result code form
V0 Enables short-form (terse) result codes.
V1 Enables long-form (verbose) result codes (default).
Wn Error correction message control
W0 Upon connection, the modem reports only the DTE speed (e.g.,
CONNECT 9600). Subsequent responses are disabled (default).
W1 Upon connection, the modem reports the line speed, the error
correction protocol, and the DTE speed. Subsequent responses are
disabled.
W2 Upon connection, the modem reports DCE speed (e.g., CONNECT
2400). Subsequent responses are disabled.