Internet PLC Forum

General => Technical support => Topic started by: temp on June 18, 2005, 08:09:49 AM

Title: time delay on relay release
Post by: temp on June 18, 2005, 08:09:49 AM

On the T100MD I close and open a relay at a certain frequency as follows:

if pulseperiod(1) < 33000 then
  setio  out1
else
  clrio out1
endif

how do I insert a delay (say 5 seconds) before the relay releases?  I need a certain amount of hysteresis in the circuit.
 

Title: Re:time delay on relay release
Post by: support on June 20, 2005, 03:42:56 PM

You can use Out1 to trigger a timer (lets call it T1)

Then before you execute the CLRIO statement, perform a check:

.....
ELSE
   IF TESTIO(T1) = 1
            CLRIO OUT 1
   ENDIF
ENDIF

This way, OUT1 will not be cleared  unless T1 contact closes.