Multi-Tech Systems ISIHP-2U - Manual (Page 51)

Software/Driver Installation
MultiModemISI Hybrid Series, ISIHP-2S/2U/4S/4U/4SD 51
• Persistent DTR Dialing __________________
A high DTR (Data Terminal Ready) signal on the serial port indicates
that your computer or terminal is ready to communicate with your
TA. DTR normally goes high when a communication program starts
or is ready to dial. Persistent DTR dialing enables the TA to
automatically redial the number stored in memory location 0
whenever DTR is high, and the serial port does not have an active
call. You can enable or disable this feature. AT command: $D
• Auto Answer Data Calls _________ Rings to Answer_________
Select Auto Answer if you want the TA to automatically answer all
incoming data calls (option does not affect analog port). The Rings to
Answer number (range: 1—255) selects number of rings the TA waits
before answering an incoming call. Default: 1 ring. AT command:
S0=
• Dialing Method ________________________
Select either the Enbloc or the Overlap dialing method for use when
establishing a data call. Your ISDN provider determines the dialing
method. The enbloc method is used for most ISDN dialing; however,
you can select the overlap method if you are working with a private
network. AT command: %A97=
• Data Protocol _________________________
The data protocol, also known as the B-channel protocol and the rate
adaptation protocol, is the language spoken over each 64 Kbps
channel between two ISDN devices. The devices on both ends of the
ISDN link must use identical protocols. AT command: !Z
V.120 Protocol—provides rates up to 64000 bps on each B channel.
PPP Protocol—provides rates up to 64 Kbps per channel.
V.110 Protocol— a rate adaptation protocol that adapts the rates of
slower asynchronous terminals to the data rate of the ISDN B-
channels. 9600 bps V.110 connections are supported by the ISIHP
products for compatibility with digital calls originating from GSM
networks.