Sequencing Discrete Outputs without using an Event Sequence

Issue

Need to sequence several outputs to be on for 10 seconds then off for 15 then the next on for 10 and so on, but the site has specified no event sequences are to be used.

Product Line

TAC I/NET

Environment

I/NET

DDC

Cause

Need to sequence several outputs to be on for 10 seconds then off for 15 then the next on for 10 and so on, but the site has specified no event sequences are to be used.

Resolution

  1. Create a DDC relay for output 1 that is an interval timer relay with the time set to 10 (time the device is on) Set the DI select to an input trigger point
  2. Create a second DDC relay to function as a delay before make relay. Set its time to 25 seconds, or the device on time plus the interval time before the next output. Set the output of this relay as a Line and the DI select as the trigger point.
  3. Copy the DDC relay from step 1. Change the DI select to the line from the previous step and the Output to the next device in the series.
  4. Copy the DDC relay from step 2. Change the DI select to the output triggered in the previous step and change the Output to a new line.
  5. Copy the DDC relay from step 1. Change the DI select to the line from the previous step and the Output to the next device in the series.
  6. Copy the DDC relay from step 2. Change the DI select to the output triggered in the previous step and change the Output to a new line.

Repeat steps 5 and 6 until you have completed the series. If you wish for this to cycle in a loop, have the output from the last Relay trigger the DI point which starts the series. If this is an internal point you may want to add a calc to keep it equal to 0.