4.17 - DigitalIO [U12 Datasheet]

Reads and writes to all 20 digital I/O. The order of execution within the U12 is:

1. Set D states

2. Set D directions

3. Set IO states

4. Set IO directions

5. Read D states

6. Read IO states

Even more detail of the execution order with the approximate time between each step:

1. Set D7-D0 states

2. 1 µs

3. Set D12-D8 states

4. 2 µs

5. Set D15-D13 states

6. 0.5 µs

7. Set D7-D0 directions

8. 1 µs

9. Set D12-D8 directions

10. 1 µs

11. Set D15-D13 directions

12. 16 µs

13. Set IO states

14. 16 µs

15. Set IO directions

16. 2 µs

17. Read D7-D0 states

18. 0.3 µs

19. Read D12-D8 states

20. 0.7 µs

21. Read D15-D13 states

22. 10 µs

23. Read IO states

Execution time for this function is 20 milliseconds or less (typically 16 milliseconds in Windows).

Declaration:

long DigitalIO ( long *idnum,
long demo,
long *trisD,
long trisIO,
long *stateD,
long *stateIO,
long updateDigital,
long *outputD )

Parameter Description:
Returns: LabJack errorcodes or 0 for no error.
Inputs:

• *idnum – Local ID, serial number, or -1 for first found.

• demo – Send 0 for normal operation, >0 for demo mode. Demo mode allows this function to be called without a LabJack.

• *trisD – Directions for D0-D15. 0=Input, 1=Output.

• trisIO – Directions for IO0-IO3. 0=Input, 1=Output.

• *stateD – Output states for D0-D15.

• *stateIO – Output states for IO0-IO3.

• updateDigital – If >0, tris and state values will be written. Otherwise, just a read is performed.

Outputs:

• *idnum – Returns the local ID or –1 if no LabJack is found.

• *trisD – Returns a read of the direction registers for D0-D15.

• *stateD – States of D0-D15.

• *stateIO – States of IO0-IO3.

• *outputD – Returns a read of the output registers for D0-D15.