A–B
18
Chapter
18–1
I/O Message and Communication Instructions
This chapter discusses the following output instructions.
•
Instructions for use with fixed, SLC 5/01, and SLC 5/02 processors:
–
Immediate Input with Mask (IIM)
–
Immediate Output with Mask (IOM)
•
Instructions for use with SLC 5/02 processors only:
–
Message Read/Write (MSG)
–
Service Communications (SVC)
–
I/O Interrupt Enable (IIE)
–
I/O Interrupt Disable (IID)
–
Reset Pending I/O Interrupt (RPI)
–
I/O Refresh (REF)
IIE, IID, and RPI instructions apply to I/O event-driven interrupts, discussed
in chapter 31, Understanding I/O Interrupts – SLC 5/02 processor only.
All application examples shown are in the HHT zoom display.
SLC 5/02 Processors Only
Message Read/Write
MSG
Output Instruction
(MSG)
(EN)
(DN)
(ER)
MSG
READ/WRITE MESSAGE
Read/write
WRITE
Target Device
500CPU
Control Block
N7:0
Control Block Length
7
F1
F2
F3
F4
F5
ZOOM on MSG –(MSG)– 2.0.0.0.1
NAME: MESSAGE READ/WRITE
MSG TYPE: WRITE LD/LS ADDR:N7:40
TARGET: 500 CPU TARG NODE: 5
CTRL BLK: N7:0 TARG OS/AD:N7:6
EN ST DN ER NR TO MSG LEN: 2
0 0 0 0 0 0
EDT_DAT
HHT Ladder Display:
HHT Zoom Display:
Ladder Diagrams and APS Displays:
(online monitor mode)
Message Instruction (MSG)