Owner's manual

Chapter 4: PowerDAQ Software

Input/Output Mode

Single Update

The PowerDAQ DIO boards operate with either a single-update or

streaming input configuration. Single-update inputs/output mode

allows performing direct read/write access to any of the 16-bit ports of

the DIO board. Boards without –CT and –ST suffixes in the part

number will allow this mode only for the DIO and counter/timer

operations. The update frequency is limited by the PC and operating

system performance and generally in 1K-10K range (may be higher for

the real-time OS).

Note Single Update mode is easiest way for most of DIO

applications such as Relay Control or Sensor Read.

Also, Change of State Interrupt works perfectly fine

in combination with Single Update mode. S

Appendix D: Common Questions and Support.

The general sequence of the PowerDAQ SDK function calls for this

mode is:

• Acquire all resources

• Open Driver

• Open Adapter

• Acquire Digital Input and/or Digital Output Subsystem

• Enable desired ports as an outputs

• Configure the events, if interrupts for the state change is used

• Read/Write the data from/to DIO ports

• Wait for the event to happens if interrupts are used

• Release all resources used

• Close subsystem

• Close Adapter

• Close driver