Patton electronic 2500 Series User Manual

Page 7

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Character Length

In asynchronous data format, 10 and 11 bit characters are

supported. This setting is ignored in synchronous data format.

Character

Character Description

SW1-6

Length

Start

Data bits

Parity

Stop bits

Off

10-bit

1

8

None

1 or more

1

7

1

1 or more

1

7

None

2

On

11-bit

1

8

1

1 or more

1

9

None

1 or more

Data Format

The data format selection controls whether an async-to-sync

conversion is performed. (Data is always transferred synchronously
between the two CSU/DSU’s)

SW1-7

Data Format

On

Asynchronous

Off

Synchronous

Note

1

: The async rate of 57.6 kbps is supported at the 56kbps line

rate, provided the DTE equipment transmits two stop bits. Two stop
bits can be configured on most DTE equipment. This extra stop bit
reduces the DTE’s effective data rate by a few percent to allow
synchronization with the 56kbps line speed.

Note

2

: Lower speed asynchronous data can be transmitted on

synchronous circuits by simple over-sampling. To do this, leave Data
Format set to synchronous. Make sure the CSU/DSU’s sync data rate
is at least 4 times more than the async data rate you wish to send.

DSR Loop Status

The behavior of the DSR output during performance of a local

loop can be controlled.

DSR

SW1-8

Loop Status

Description

On

DSR On

DSR remains high (On) during the
Analog Loop

Off

DSR Off

DSR goes low (Off) during the
Analog Loop

4.1.2 SWITCH SET SW2

The configuration switches on switch SW2 control the Rate

Adapter/DTE Rate, Clock Mode, Anti-Stream Timer and RTS/CTS
Delay. Figure 5 (below) summarizes SW2 switch settings, including the
factory defaults. Following Figure 4 is a description of each switch
setting.

Rate Adapter/DTE Rate

The Model 2500 Series includes a rate adapter that allows the unit

to be used with DTE devices that support rates lower than 56/64 kbps.
All switch settings below are valid for line rates of 56 or 64 kbps.

SW2-1

SW2-2

SW2-3

DTE Rate

On

On

On

2.4 kbps

Off

On

On

4.8 kbps

On

Off

On

9.6 kbps

Off

Off

On

19.2 kbps

On

On

Off

38.4 kbps

Off

Off

Off

Line Rate = DTE Rate

Note: for DTE devices that operate at 57.6 kbps, set the Line Rate to
56 kbps (see Section 4.1.1), set the rate adapter for “Line Rate=DTE
Rate”, and configure your DTE device for two stop bits (set character
length accordingly).

12

11

SWITCH SET 2 SUMMARY TABLE

Figure 4. Summary of switch settings, showing factory defaults

Position

Function

Factory Default

Switch SW2-1

Rate Adapter/

Off

Switch SW2-2

DTE Rate

Off

Switch SW2-3

Off

Switch SW2-4

DTE

Loop Control

Off Disabled

Switch SW2-5

Clock

Mode

Off

Off

Switch SW2-6

Off

On

Switch SW2-7

Anti-Stream Timer

On Disabled

Switch SW2-8

RTS/

CTS Delay

Off Normal

Model 2510

Switched 56

}

Network
Clock

}

DTE Rate

}

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