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DATABUFFER PLUS
The DataBuffer Plus monitors Pin 20 for activity from the output device. When
the device attached to the output port cannot accept any more data, it drops Pin
20. When the output device is ready to accept more data, it returns Pin 20 to a high
level to the DataBuffer Plus.
4.2.2 X-ON/X-OFF H
ANDSHAKING
When the unit’s buffer is almost full, it sends an X-OFF character to the input
device via Pin 2. The unit sends an X-ON character via Pin 2 once the output
device has accepted enough data to leave room in the buffer for more input data.
When the output device cannot accept any more data, it sends an X-OFF
character to Pin 2 on the DataBuffer Plus’s output port. When the output device
is ready to receive more data, it sends an X-ON character via Pin 2.
4.3 DataBuffer Plus Input and Output Port Pinouts
Serial Pin Configurations (Input Port DTE) DB25 Female.
Pin
Name
Source
Function
1
FG
Chassis ground
2
TD
Buffer unit
Output from buffer
3
RD
Input device
Input to buffer
4
RTS
Buffer unit
Request to send (Held High)
5
CTS
Input device
Input to buffer
7
GND
Signal Ground
20
DTR
Buffer unit
Output from buffer (hardware
handshaking pin)
Serial Pin Configurations (Output Port DCE) DB25 Female.
Pin
Name
Source
Function
1
FG
Chassis ground
2
TD
Output device
Input to buffer
3
RD
Buffer unit
Output from buffer
5
CTS
Buffer unit
Output from buffer
6
DSR
Buffer unit
Held high tied to 8
7
GND
Signal Ground
8
CD
Output device
Held high tied to 6
20
DTR
Buffer unit
Input to buffer (hardware
handshaking pin)
Summary of Contents for PI405A
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