Control logic opening skylight

[UnknownFdsUser]

Hi everyone,

I need to create a specific control (18.5 Advanced Control Functions: The CTRL Namelist Group). A skylight must open after 1050 seconds, but only if the temperature monitored by the AST device does not exceed 55 °C. Is this possible in FDS?
After reading the FDS User Guide, I wasn’t able to figure out the FDS code.
Thanks in advance

[drjfloyd]

I find that a good way to work out control logic is start from the final step and work backwards:

Final step the skylight opening.
Step before the AST <=55 and Time > 1050 s.

Now think about how those steps can be broken down into simple logic elements and FDS inputs

Final step:
-What is the FDS input that would open a skylight based on the state of some CTRL or DEVC?
Step before:
-You have an "and" - what CTRL or DEVC does this?
-You have AST <=55 - what CTRL or DEVC does this?
-You have Time > 1050 s - what CTRL or DEVC does this?

[drjfloyd]

Also start with a simple test case. You don't need your full geometry. You could have a 1 x 1 x 1 box with 10 x 10 x 10 cells with a VENT and have the time be 2 s rather than 1050 s. Something like this will run in a couple of seconds.

[UnknownFdsUser]

thank you drjfloyd

I created a simpler scenario. A room with a door and a temperature device. The door is supposed to open at the 100 second if and only if the temperature is below 80°C.

I create a temperature sensor.
TRIP_DIRECTION=1 is activated only if T>80°C
LATCH=TRUE. Once activated, it remains locked
&DEVC ID='temp', QUANTITY='TEMPERATURE', XYZ=4.5,9.3,2.3, SETPOINT=80.0, TRIP_DIRECTION=1, LATCH=.TRUE./

I set a time delay of 100 seconds
&DEVC ID='delay', QUANTITY='TIME', XYZ=0.0,0.0,0.0, SETPOINT=100.0/

I'll set up a control to activate both devices
&CTRL ID='and', FUNCTION_TYPE='ALL', LATCH=.TRUE., INPUT_ID='delay','temp'/

but it isn't working...