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Appendix A
ASCII Module with ControlLogix System Application Examples
38
Receive Data From the ASCII Modules
To receive data from the master scanner through the ASCII modules, look for
the Receive Record Number in byte 1 to change in value. When this happens, a
new data buffer is available for storage. Read the length of the data from byte 4
and copy that number of bytes from the data buffer starting at byte 5 into a file.
Read Data from the ASCII Modules into ControlLogix
For this example, Controller Tags Edit Tags function is used to separate the
header bytes into their own data locations.
record number is in AENTR_IP85:1:I.ReceiveRecordNumber and the length is
in AENTR_IP85:1:I.Length. The ASCII data starts in AENTR_IP85:1:I.Data[0].
Figure 1 - Receive Record Number Location in Controller Tags Dialog
In
Figure 2 on page 39
record number in AENTR_IP85:1:I.ReceiveRecordNumber has changed from a
previously stored value. If it has changed, the data starting in
AENTR_IP85:1:I.Data[0] is copied to a file and the current receive record
number is stored into a data location.
Rockwell Automation Publication 1734-UM009C-EN-P - August 2022
Figure 1
the ControlLogix ladder logic checks to see if the receive
illustrates that the receive
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