Transmiter/receiver problems or ...?
10-01-2008, 03:07 PM
#1
Member
Thread Starter
My Feedback: (21)
Join Date: Jun 2002
Location: Brooklyn,
NY
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
Transmiter/receiver problems or ...?
Greetings,
Yesterday was a second time when we have a crash due to radio locked out. 2 month ago one of my friends while flying his U-CAN-DO experience complete radio lock out. Plane went to fail safe mode and circle around for more than 5 minutes before gravity won this fight. Yesterday the same happened to another person's plane. This time it was 50cc. It also stays in the air for about 5 minutes before hitting the ground. In both cases flyers try to cycle power on the radios trying to get the controls back, but they were unsuccessful. Both of them using 9CAP with standard modules (Channels 22 and 34). They also have PCM receivers in the planes ( 9 channels) with fail safe set up. Batteries was charged before the flights and inspected after the crash. Both has sufficient amount of power left, not to mention that 50cc has 2 batteries for receiver for additional redundancy. Other equipment was checked for loose connections or failed servos, but everything works just fine. After both planes was recovered and the power on the receiver was cycled, radio was able to control all the servos w/o any problems. I am not sure why it's happening, I just have a suspicion that this might be a "human" related problems, but I just want to confirm; if someone turning on the radio on the same channel while you are flying, what is going to happened? Will the PCM locked out and go in the fail safe mode; and stay in that mode even that the second transmitter will be switched off after some time? Will the "closer" transmitter "wins" and would be able to control the plane with some minor glitches until plane reaches second transmitter and that second transmitter becomes "master"? Please give me more information on the fail safe feature and how it works. Thank you in advance.
Yesterday was a second time when we have a crash due to radio locked out. 2 month ago one of my friends while flying his U-CAN-DO experience complete radio lock out. Plane went to fail safe mode and circle around for more than 5 minutes before gravity won this fight. Yesterday the same happened to another person's plane. This time it was 50cc. It also stays in the air for about 5 minutes before hitting the ground. In both cases flyers try to cycle power on the radios trying to get the controls back, but they were unsuccessful. Both of them using 9CAP with standard modules (Channels 22 and 34). They also have PCM receivers in the planes ( 9 channels) with fail safe set up. Batteries was charged before the flights and inspected after the crash. Both has sufficient amount of power left, not to mention that 50cc has 2 batteries for receiver for additional redundancy. Other equipment was checked for loose connections or failed servos, but everything works just fine. After both planes was recovered and the power on the receiver was cycled, radio was able to control all the servos w/o any problems. I am not sure why it's happening, I just have a suspicion that this might be a "human" related problems, but I just want to confirm; if someone turning on the radio on the same channel while you are flying, what is going to happened? Will the PCM locked out and go in the fail safe mode; and stay in that mode even that the second transmitter will be switched off after some time? Will the "closer" transmitter "wins" and would be able to control the plane with some minor glitches until plane reaches second transmitter and that second transmitter becomes "master"? Please give me more information on the fail safe feature and how it works. Thank you in advance.
10-01-2008, 03:49 PM
#2
My Feedback: (11)
RE: Transmiter/receiver problems or ...?
If you have two transmitters on the same channel turned on at the same time, no receiver in the vicinity will operate properly. It doesn't matter whether it's a PCM or PPM receiver. The PCM will lock out then go into failsafe, and the PPM receiver will make the servos go crazy.
If the interfering transmitter is turned off, the PCM receiver will come out of lockout/failsafe after about a second or so, the PPM receiver will immediately start sending good signals to the receiver.
Failsafe is a feature of PCM systems. It allows you to set control positions of the different channels so that they will move to that position when a coherent signal is lost. With giant airplanes, throttle to idle is usually required, and with jets, engine off is required. Many people just set controls to neutral because no matter what control positions you use, the model will still get disturbed in the air and wind up heading for the ground, so why put in controls to hold a turn? It depends upon your philosophy for setting up models.
If the interfering transmitter is turned off, the PCM receiver will come out of lockout/failsafe after about a second or so, the PPM receiver will immediately start sending good signals to the receiver.
Failsafe is a feature of PCM systems. It allows you to set control positions of the different channels so that they will move to that position when a coherent signal is lost. With giant airplanes, throttle to idle is usually required, and with jets, engine off is required. Many people just set controls to neutral because no matter what control positions you use, the model will still get disturbed in the air and wind up heading for the ground, so why put in controls to hold a turn? It depends upon your philosophy for setting up models.
