Rockwell Automation 1746-BAS BASIC LANGUAGE - Manual (Page 157)

Publication 1746-RM001A-US-P
Output Functions 12-7
If an internal string is chosen, the first character (transaction number) is
incremented on successful completion of the write to inform the module that data
was sent. The value of the transaction number wraps around from 255 to 0.
Execute CALL 28 once to set up the data transfer parameters. Input and output
image bits (word 0, bit 11) for the slot containing the module, are used to initiate
and notify completion of the transfer. The operation is described below:
1. 1. 1. 1. The local SLC processor builds the data buffer.
2. 2. 2. 2. The SLC processor sets output file word 0, bit 11 to inform the module that
data can be transferred.
3. 3. 3. 3. The module transfers the data into the remote data buffer.
4. 4. 4. 4. The module places the transfer status into the input file word 1, bits 0-7.
5. 5. 5. 5. The module sets the input file word 0, bit 11 to inform the local SLC
processor that valid data is transferred and the status of the transfer is available.
DATA BUFFER
SLC Processor
Output File
Word 0, Bit 11
SLC Processor SLC Backplane BASIC or BASIC-T Module
SLC Processor SLC Backplane BASIC or BASIC-T Module DH485 Network Remote Device
DESTINATION
BUFFER
PORT DH485
DATA
BUFFER
Input File Word 1,
Bits 0 through 7
SLC Processor SLC Backplane BASIC or BASIC-T Module