Option b switches, Baud switches – CTI Products NCB/EM with External PSTN Modem User Manual
Page 16
CTI Products, Inc.
NCB-EM User Guide
2. Setup and Operation
10
If OPTION A Switch 5 is DOWN, dynamic determination of the domain/subnet/node number by a
Network Management Tool is allowed.
OPTION B Switches
OPTION B switches set the Automatic Answer feature of the dial-up type external modem and Serial Port
Handshaking options.
1. PORT 1 Auto Answer Mode .............Disabled
Enabled (Normal)
2. PORT 1 DSR sense .........................Disabled
Enabled (Normal – Leave UP for Leased-Line)
3. PORT 2 Auto Answer Mode .............Disabled
Enabled (Normal)
4. PORT 2 DSR sense .........................Disabled
E
nabled (Normal – Leave UP for Leased-Line)
DOWN
UP
1
2
3
4
ON
A dial-up type external modem can be commanded to dial out regardless of its’ Auto Answer Mode
Enable/Disable setting.
DSR/DTR handshaking informs the NCB that a connected device is active. If the channel does not directly
support DSR/DTR handshaking, DSR must be strapped back to the (always active) DTR output signal.
When enabled, the operation of DSR/DTR is as follows:
Signal
Direction
Function
DSR
Input to NCB
Active when a connected device is functioning.
This signal is driven by the connected device’s DTR signal.
If driven inactive, NCB front panel “ERR” LED will flash quickly, and NCB
will not communicate with this device.
If DSR signal is not available from connected device, strap to DTR output.
DTR
Output from
NCB
Always driven active by NCB.
BAUD Switches
“BAUD 1” and “BAUD 2” switches correspond to “PORT 1” and “PORT 2” connectors and allow either
disabling the port for use or enabling it at a specific baud rate.
Position
Function/Baud Rate
0
Disable Port
1
1200 Baud
2
2400
3
4800
4
9600
5
19200
6
38400
7
57600
8
115200
NOTE: Set the “BAUDn” switch to 0 if the respective port will not be used. This is
important, as the front panel “ERR” LED will flash continuously if a serial port “BAUD”
switch is non-zero and no modem is connected.
8 9
7
A
B
C
D
E
F
0
1
2
3
4
5
6
8 9
7
A
B
C
D
E
F
0
1
2
3
4
5
6
BAUD 1
BAUD 2