S2 Position 2: 2-Wire vs. 4-Wire Operation
, determines whether the Multi-Function LD Card operates in 2-wire or 4-wire mode.
S2-2
Operation:
OFF
4-Wire (full- or half-duplex) (default)
ON
2-Wire (half-duplex only)
S2 Position 3: V.52 and V.54 Diagnostic Testing.
To reset the V.54 circuit, turn switch S2 position 3 ON, then back OFF.
S2-3
Test Mode:
OFF
Normal Operation (default)
ON
Test Disabled
S2 Positions 4 and 5: RTS/CTS Delay
determines the amount of time the Multi-Function LD Card waits after it "sees" RTS before it sends CTS. Possible settings are no delay, 7 ms, or 53 ms.
S2-4
S2-5
RTS/CTS Delay:
ON
ON
7 ms (default)
ON
OFF
53 ms
OFF
ON
No Delay
OFF
OFF
No Delay
S2-6: Signaling-Rate Range,
determines the degree of asynchronous data-rate fluctuation that the Multi-Function LD Card will accept (that is, how much variance from a given frequency level the Card will tolerate).
S2-6
Signaling-Rate Range:
OFF
-2.5% to +1% (default)
ON
-2.5% to +2.3%
S2-7 and S2-8: Word Length
, determines the word length that the Multi-Function LD Card will expect for synchronous or asynchronous data. For example, if you are using the most common data format (1 start bit, 8 data bits, 1 stop bit, and no parity), you would
use the factory-default word-length setting (10 bits).
S2-7
S2-8
Word Length:
ON
OFF
8 bits
ON
ON
9 bits
OFF
OFF
10 bits (default)
OFF
ON
11 bits
Configuration Switch "S3"
Use the individual positions on DIP switch S3 to set antistream control, receive (input) impedance, and point-to-point/multipoint, as well as to enable or disable local and remote loopbacks. The factory-default settings are summarized in the table below.
POSITION
FUNCTION
DEFAULT SETTING
S3-1
S3-2
Input Impedance
Input Impedance
On
200 ohms
Off
200 ohms
S3-3
Reserved
N/A
S3-4
Point-to-Point/Multipoint
On Point-to-Point
S3-5
DTE Local Loopback
Off
Disabled
S3-6
DTE Remote Loopback
Off
Disabled
S3-7
S3-8
Antistream Control
Antistream Control
Off
Disabled
Off
Disabled
