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.