Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 213)

Application Example 2, Periodic Block
Transfer
Appendix C
CĆ29
AN 'ON' STATE OF EITHER OF THE TIMER ONEĆSHOT BITS (T0/16 AND T1/16) OR THE
STATUS MONITOR BYTE OUTPUT INDICATOR WILL CAUSE STORAGE BIT W0001:0000/00 TO BE
LATCHED. THIS BIT IS EXAMINED IN RUNG 15 TO LATCH THE 'LOAD' BIT AND BEGIN THE
LOAD/ENTER SEQUENCE.
00004
T0000
16
W0001:0000
00
L LBL
W0001:0000
00
T0001
16
O0013
03
RUNG NUMBER RM4
TE
TD
T0002
17
T0002
15
TON
TIMER ON
0.1 SECOND
TP =
TA = 125
30
T0002
W0001:0000
00
W0001:0000
00
LBL
T0002
15 00005
STORAGE BIT W0001:0000/01 IS LATCHED WHEN FREEĆRUNNING TIMER T2 'TIMES OUT.' BIT W0001:0000 IS USED AS
THIS FREE-RUNNING TIMER ALLOWS A READ BLOCK TRANSFER TO OCCUR AT A USER SELECTABLE TIME
INTERVAL AS DETERMINED BY THE FREE-RUNNING TIMER PRESET VALUE. (*NOTE* - THIS TIMER WILL
BE RESET DURING THE EXECUTION OF A LOAD/ENTER SEQUENCE BECAUSE STORAGE BIT W0001:0000 WILL
BE ON).
RUNG NUMBER RM5
RUNG NUMBER RM 6
A PRECONDITION TO THE BLOCK TRANSFER READ INSTRUCTION IN RUNG 7.
LBL
00006
T0002
15
L
W0001:0000
01
Figure C.7 - PLC-3 Periodic Block Transfer Program (Cont.)
Figure C.7 - PLC-3 Periodic Block Transfer Program (Cont.)