Rockwell Automation 57C409 2 Channel Analog Input Module - Manual (Page 23)

4Ć7
4.4.1 BASIC Task Example
The following is an example of a BASIC task that handles interrupts
from channel 0 from the input module.
1000 !
1002 ! common data declarations
1003 !
1004 COMMON ANALOG INPUT 0% \!Data from channel 0
1005 COMMON ISCR CHANNEL 0% \!Interrupt status & control 0
1010 COMMON CCLK ENABLE 0@ \!Common clock enable 0
1015 COMMON CCLK ENABLE 1@ \!Common clock enable 1
1020 COMMON UPDATE TIME 0% \!Update period for channel 0
1025 COMMON INPUT 0 FILTERS% \!Input filter for channel 0
1100 !
1150 ! local data declarations
1175 !
1200 LOCAL ANALOG VALUE% \!Analog value
2000 !
2001 !set up the conversion parameters
2002 !
2011 INPUT 0 FILTER% = 2 \!79 rad/sec filter
2900 !
2950 ! The following statement connects the name CHANNEL 0 EVENT
3000 ! to the interrupt defined in ISCR CHANNEL 0%. The event name
3001 ! should be as meaningful as possible. The watchdog timeout has
3002 ! been set to 120 clock ticks (660 msec). 1 tick
3003 ! equals .0055 seconds. If the time between
3004 ! interrupts exceeds this value, a bus error will
3005 ! be indicated on the processor's LED and the system
3006 ! will be stopped. For more information refer to
3007 ! the Enhanced BASIC Instruction manual (JĆ3675).
3008 !
3010 EVENT NAME=CHANNEL 0 EVENT, &
INTERRUPT STATUS=ISCR CHANNEL 0%, TIMEOUT=120
4000 !
4001 UPDATE TIME 0% = 1000 \!Convert every .5 seconds
4002 ! The following statements enable common clock" on this module.
4003 ! If there is more than one interrupt task in a chassis, the
4004 ! task that enables common clock" should always be the lowest
4005 ! priority task.
4006 !
4010 CCLK ENABLE 0@ = TRUE \!Turn on the clock
5000 !
5001 ! Place any additional initialization statements here
5002 !
6000 !
6001 ! The next statement synchronizes the task with the external
6002 ! event via the interrupt. Task execution will be suspended
6003 ! until the interrupt occurs. If this task is the highest
6004 ! priority task waiting to execute at the time of the
6005 ! interrupt, it will become active. If it is not the highest
6006 ! priority task, it will remain suspended until all higher
6007 ! priority tasks have executed, at which point it will become
6008 ! active.
6009 !
6010 WAIT ON CHANNEL 0 EVENT
7000 !
7001 !
7002 ! The next statement performs the interrupt service routine
7003 !
7010 ANALOG VALUE% = ANALOG INPUT 0%
8000 GOTO 6010
10000 END