Rockwell-automation 1775-KA PLC-3 Communication Adapter Module User Ma Bedienungsanleitung PDF herunterladen (Seite 157)

Network and Application Layer Protocols

Chapter 12

1210

ADDR (address)

The address field in command messages can be in one of the following

formats:

PLC/PLC–2 addressing format

Symbolic addressing format

Logical addressing format

Physical addressing format

The PLC/PLC–2 addressing format applies to PLC/PLC–2 type

commands transmitted to the 1775–KA module. Use this addressing

format whenever you have established a PLC–3 input file to imitate

PLC/PLC–2 memory (section titled PLC/PLC–2 Stations, chapter 3).

The ADDR (address) field is a 2–byte address field sent low byte first.

PC programs use logical addressing to specify octal bytes. To generate a

protected/unprotected read/write command, use that same octal addressing

to format the ADDR field as shown in Figure 12.4. For a block read/write

command, always set the least significant bit to 0 to select the low byte of

the word. To allow PC read/write commands to the computer, set up a file

in the computer to be addressed in this same way as if it were a PC data

table.

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Rockwell-automation 1775-KA PLC-3 Communication Adapter Module User Ma Bedienungsanleitung Seite 157