Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE - Manual (Page 85)

ASCII I/O Module Tutorial
Chapter 4
4Ć11
Notice the following:
The new string (data and fill characters) completely replaced the
previous data.
The data is right justified.
Fill character spaces (20) were added by the ASCII module.
String Length Greater Than Module's String Length
When the module receives a string of data greater than the set string
length, it does the following:
Immediately transfers the number of characters equal to its set string
length to the processor.
Sets bit 14 in status word one, Input String>Maximum, SW1(14). Bit
14 is immediately reset when the processor confirms receipt of data.
Retains the balance of data in its input buffer.
Transfers the balance of data with new data when it receives enough
new data to complete the string, or when the new data contains an
end-of-string delimiter.
In this demonstration you will enter a string of data greater than the set
string length and observe its storage in the data table. (The set string
length, IW2(00-13), is 15 characters.)
1. Enter 12345678901234567890
Do not enter [RETURN]
Refer to procedures in section titled “Reading Data from Your ASCII
Device”, P. 1-10.
Procedure P1 Set your industrial terminal to alphanumeric mode
Procedure P2 Enter your data
Procedure P3 Set your industrial terminal to PLCĆ2 mode
Procedure P4 Observe how data is stored in the data table
Results The read block transfer file displays the number of characters
equal to the string length, 15, in positions 003 thru 010 (Table 3.F).