Rockwell-automation 20-COMM-I Interbus Adapter Instrukcja Użytkownika Pobierz pdf (Strona 77)

Using Explicit Messaging (PCP Communications) 6-15

PCP Read Subroutine (Explicit Messaging)

The PCP Read Subroutine is executed from the Main Program (Chapter

5) by turning on bit B3:47/0. Only one PCP Read or Write can be

performed at any one time. B3:47/0 will be turned off by the subroutine

when the reading is complete and signals that another read (or write)

cycle can take place.

Figure 6.3 LAD5 - PCP Read Subroutine

SLC Ladder Example - Peripheral Communications

Protocol (PCP)

N22:10 = PCP Command Word (Always set to "4" to cause a PCP Read: a "4" = bit 2 ON)

0000

B3:47

PCP Read

Routine

1-shot

MOV

Move

Source 4

Dest N22:10

MOV

PCP

Command

Word

N22:11 = The Communication Reference (CR) to read from. There is a unique CR for each Station.

"2" = CR 2 = Station 1.0

"3" = CR 3 = Station 2.0

0001

B3:47

PCP Read

Routine

1-shot

MOV

Move

Source N22:0

Dest N22:11

MOV

PCP Read

Command Msg

20COMM-UM007A-EN-P.book Page 15 Tuesday, January 22, 2002 10:52 AM

1 2 ... 72 73 74 75 76 77 78 79 80 81 82 ... 117 118

Brak uwag

Rockwell-automation 20-COMM-I Interbus Adapter Instrukcja Użytkownika Strona 77