Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 252)

Preface MicroLogix 1000 Programmable Controller User Manual
13–4
•
Control Block Address – an integer file address that you select. It consists of 7
integer words, containing the status bits, target file address, and other data
associated with the MSG instruction.
•
Control Block Length – fixed at seven elements. This field cannot be altered.
Note When running a MicroLogix 1000 program on an SLC 5/03 or SLC 5/04
processor, or on channel 0 of an SLC 5/05 processor, the MSG control block
length increases from 7 to 14 words. If you plan to run a MicroLogix 1000
program with one of these processors, make sure that the program has at least 7
unused words following each MSG control block.
The table that follows illustrates combinations of message types and target devices
and their valid file types.
Command Type
Message
Type
Initiating
Device
Valid File
Types
Target
Device ➀➁➂
Valid File Types
SLC500/ML1000 Write MicroLogix 1000 O,I,S,B,T,C,R,N MicroLogix 1000 O,I,S,B,T,C,R,N
SLC500/ML1000 Read MicroLogix 1000 O,I,S,B,T,C,R,N MicroLogix 1000 O,I,S,B,T,C,R,N
CIF Write MicroLogix 1000 O,I,S,B,T,C,R,N MicroLogix 1000 N7
CIF Read MicroLogix 1000 O,I,S,B,T,C,R,N MicroLogix 1000 N7
SLC500/ML1000 Write MicroLogix 1000 O,I,S,B,T,C,R,N SLC 500 O ➃ ,I ➃ ,S,B,T,C,R,N
SLC500/ML1000 Read MicroLogix 1000 O,I,S,B,T,C,R,N SLC 500 O ➃ ,I ➃ ,S,B,T,C,R,N
CIF Write MicroLogix 1000 O,I,S,B,T,C,R,N SLC 500 N9
CIF Read MicroLogix 1000 O,I,S,B,T,C,R,N SLC 500 N9
➀
The DF1 Full-Duplex protocol can be used if the target device supports it. Such devices include MicroLogix 1000
controllers (any series), SLC 5/03, SLC 5/04 and SLC 5/05 processors, and PLC-5 processors (CIF command
type only).
➁
The DH-485 protocol can be used if the target device supports it. Such devices include MicroLogix 1000
controllers (except for Series A and B discrete controllers) and SLC 500, SLC 5/01, SLC 5/02, SLC 5/03, SLC
5/04 or SLC 5/05 processors.
➂
The DF1 Half-Duplex protocol can also be used with Series D or later discrete and all analog MicroLogix 1000
controllers, but a master is required, such as an SLC 5/03, SLC 5/04 or SLC 5/05 processor.
➃
SLC 500, SLC 5/01, and SLC 5/02 processors do not support O or I file access from a MSG instruction.
SLC 5/03, SLC 5/04 and SLC 5/05 processors do support O and I file access, but only when unprotected.