How do I adjust a DEI 528T pulse timer relay?

My DEI main control/alarm doesn't have a connection for the green warn-away wire; it only has a blue trigger wire. I wanted to use the warn-away feature of the DEI 508D Dual Zone Motion Sensor, so I connected the green wire directly to my siren, but the 1/2 second pulse isn't enough to give a warning chirp. I then installed a 528T Pulse Timer Relay to increase the length of time the siren is on. Everything works except the time the siren stays on too long. I tried to turn the adjustment knob all the way to the right than the left, but the relay stays on. How do I adjust the 528T relay? The instruction sheet doesn't say anything. My connections are as follows. 528T ------- Connection Red -------- +12V fused Black ------ -12V Ground Blk/Wht ---- Green Wire from 508D Orange ----- ** Not Used ** Yellow ----- -12V Ground (connected to the same point as the Black wire above) Brown ------ Siren (-12V side. Positive side of siren is constant +12V) Blue ------- ** Uncut ** Also... I thought about connecting the Yellow and Black wires to the "Negative When Armed" Orange wire from the alarm's controller/brain, but I wasn't sure if the alarm's on-board relay can handle the amperage. The 528T has a 15A relay, but I doubt my siren will need that much. The installation manual for my alarm doesn't say what the maximum amperage the alarm's orange wire can handle. It does give a 200mA warning for 2 other wires/on-board-relays. Does the 528T use a lot of power when it is idle, or can I leave it connected to power all the time? Thank you.