Rockwell-automation 1746-BAS BASIC LANGUAGE User Manual download pdf (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. The local SLC processor builds the data buffer.

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. The module transfers the data into the remote data buffer.

4.4.

4. The module places the transfer status into the input file word 1, bits 0-7.

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

1 2 ... 152 153 154 155 156 157 158 159 160 161 162 ... 279 280

No comments

Rockwell-automation 1746-BAS BASIC LANGUAGE User Manual Page 157