Chapter 3 – Voice Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (S000273G) 29
Description: This command enables or disables automatic hang ups.
Syntax: +VNH=<hook>
Values: <hook> Decimal number corresponding to the selected option.
0 Modem enables automatic hang ups as is normal in other modes.
1 Modem disables automatic hang ups usually found in the other non-
voice modes.
2 The modem disables automatic hang ups in the other non-voice modes.
The modem performs a “logical” hang up (returns OK result code).
Default: 0
Report Commands: +VNH? Reports current or selected values.
+VNH=? Reports supported range of parameter values.
Command Responses:
A
utomatice Hang-up Command Responses
Command No Carrier Present
A
TH ATZ DTR & D2
+VNH=0 Y Y Y Y
+VNH=1 N Y Y Y
+VNH=2 N N N Y
Notes:
Y = will hang up; N = will not hang up
How +VNH is reset:
DTE uses +VNH command to change the setting.
DTE issues another +FCLASS mode change without issuing another +VNH.
A hang-up event occurs (see this table).
DTE issues +VIP command.
Function: Select Flow Control Method
Values: 0, 1, 2, 3-255
Result Codes: OK or ERROR
Description: The +FLO? command lets you select the method of flow control provided and used by the
modem. If +FLO=0, some other method (such as credit flow control) is used. The Xon-Xoff
method is required. Xon is the ASCII character <DC1> (11 hex). Xoff is the ASCII
character >DC3> (13 hex). CCITT V.24 circuits 106 and 133 are optional flow control
methods. If circuits 106 and 133 are not used (+FLO<>2), then circuit 106 is held On
whenever +FCLASS=8.
In Voice mode, circuit 105 has no effect on the state of transmitted data. (Circuit 133
normally reverts to use as circuit 105 (RTS) when not used for Flow Control.)
+FLO=0 Disables Xon-Xoff and 133/105 flow control
+FLO=1 Enables Xon-Xoff flow control in either direction
+FLO=2 Enables CCITT Circuit 133 for flow control of the modem by the PC; use
CCITT Circuit 106 for flow control of the PC by the modem.
+FLO=3-255 Reserved for future standards.