Multi-Tech Systems CF220 manual Channel Configuration Screen, Degradation of performance

Chapter 4: CallFinder Software Screens

Channel Configuration Screen

“Channel Configuration: Channel 1 & Channel 2” Screen Field Definitions

Field Name	Values	Description
Max DID Digits	1-7	The number of digits that the telco supplies to the
		DID line when an incoming call is received.
		Default = 4.
Extension Port	FXS or FXO	Denotes the interface type of the port (Channel 1
		or Channel 2). Each CallFinder port can be set
		up either as an FXS port or as an FXO port. If a
		port is configured as FXS, it would commonly be
		connected to a PBX trunk line. If a port is
		configured as FXO, it would commonly be
		connected to a PBX station line.
Extension Mic Gain	0 to 255	The degree of amplification that the CallFinder
		imposes on the voice signal of the phone
		receiving the DID call. Default = 8
		NOTE: This is a very sensitive parameter.
		Change it only if necessary and then very
		carefully. Misadjustment of this
		parameter can cause unacceptable
		degradation of performance.
Polarity	A or B	Orientation of DID battery voltage. Polarity of the
		battery voltage on the DID line is very important
		for the DID line to work properly. Since the line
		comes from the telco as a twisted pair the
		required polarity can only be determined through
		trial and error. The modem is defaulted to
		Polarity A. If an immediate busy signal is
		received when dialing a DID number or if the call
		is dropped shortly after connecting, then the
		battery polarity is probably wrong and the
		alternate battery voltage should be tried.
		Default = A.
DID Start	wink, immediate,	Indicates the signaling method that the DID line
	delay dial	uses to indicate readiness to receive digits. The
		telco must specify which ‘start type’ is to be used.
		For Wink Start, the CallFinder detects the off-hook
		condition. Then the CallFinder reverses battery
		polarity for a specified time (140-290 ms; a “wink”) and
		then becomes ready to receive DTMF digits.
		For Immediate Start, the CallFinder detects the off-
		hook condition initiated by the telco central-office call
		and becomes ready to receive DTMF digits
		immediately.
		For Delay Dial, the CallFinder detects detects the off-
		hook condition. Then the CallFinder reverses battery
		polarity for a specified time (reverse polarity duration
		has wider acceptable range than for Wink Start) and
		then becomes ready to receive DTMF digits.

Multi-Tech Systems, Inc. CF220 CallFinder User Guide 44