I understand that in order to reset the 3hr timer for cutdown, you have to move the jumper and slide the switch on the cutdown board. However, there is a phrase in the payload assembly slides that says "both OCCAMS" need to be reset. Does this mean that the Iridium modem is also on its own countdown? Will it send the termination message if it reaches zero?
So far we have only been resetting the cutdown timer.
There are indeed 2 timers that need to be reset. The Iridium modem doesn't have its own timer but the OCCAMS board that plugs into it does. The cutdown payload itself contains one timer and the other is on the OCCAMS board that plugs into the Iridium modem. Together, both timers provide backups to ensure the payloads are cut down should the time on either run out. Both timers are reset using the same instructions you referenced. If I'm not mistaken, you should reset both timers before each flight as they resume their own countdown after power is reapplied. Hope this helped.
Post by David MSGC on Jun 17, 2017 15:06:02 GMT -7
Yes, Wesley is correct, both timers need to be reset and they will continue countdown where they left off after a power cycle. This is so that it is cutdown no matter what after a certain amount of time, whether there is a power loss or any other action that cannot be controlled from the ground.