Installation manual

Publication 1747-RM001G-EN-P - November 2008
B-20 SLC Status File
S:3L
continued
Application example: Your application requires that each
and every program scan execute in the same length of time.
You measure the maximum and minimum scan times and find
them to be 40 ms and 20 ms.
You can make every scan equal to precisely 50 ms by
programming the following rungs as the last rungs of your
program.
This example assumes that your I/O scan and communication
servicing takes less than 10 ms. If it exceeds 10 ms, the
resolution of +0 to -1 tick (10 ms) must be added to the scan
time.
S:3H Dynamic
Config
Watchdog Scan Time Byte
This byte value contains the number of 10 ms ticks allowed to
occur during a program cycle. The default value is 10 (100 ms),
but you can increase this to 250 (2.5 seconds) or decrease it to
2, as your application requires. If the program scan S:3L value
equals the watchdog value, a watchdog major error will be
declared (code 0022). This value is applied each END, TND, or
REF.
•••••
Table B.2 Status File Functions (Continued)
Address Classification Description Fixed
5/01
5/02 5/03 5/04 5/05
(JMP)
]LBL[
1
1
LES
LESS THAN
Source A N7:0
Source B 5
MOV
MOVE
Source S:3
Dest N7:0
AND
BITWISE AND
Source A 255
Source B N7:0
Dest N7:0