Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE User Manual
Page 140
Function of Control/Status Bits
Chapter 6
6Ć5
Select full duplex when your ASCII device is set for full duplex, or when
your ASCII device transmits and receives data simultaneously. You can
also select full duplex when your ASCII device only transmits or only
receives data.
Select half duplex when your ASCII device is set for half duplex, or when
your ASCII device transmits or receives data one way at a time.
Select simplex read when your ASCII device only transmits data. You
should set the ASCII module’s I/O buffer to 100% input in IW3(00-02).
Select simplex write when your ASCII device only receives data. You
should set the ASCII module’s I/O buffer to 100% output in IW3(00-02).
Select echo when you want your ASCII data terminal to display the
characters it sends to the module.
Do not select echo when your ASCII device cannot display the characters
it sends to the module.
Bits: IW1(10-12)
Function: Communication Rate
Description: The communication rates that the module can handle are
listed below. Select the rate that you chose for your ASCII device.
12
11
10
Communication
Rate
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
300 baud
600 baud
1200 baud
2400 baud
4800 baud
9600 baud
110 baud
110 baud
Bit: IW1(13)
Function: Number of Data Bits
Description: Reset it to zero (default) when your ASCII device generates
8 data bits per character. Set it when your ASCII device generates 7 data
bits per character. Note that the module treats all input data as 7-bit
ASCII characters.