Here's a cautionary message for those using cendence controllers with Pro Systems.  In 2018 my research team and I lost our new (ish) Matrice 210 when it suddenly spiraled down without warning, landing in the ocean and sinking.  The incident was puzzling at the time because the drone was nearby and I (the operator) and several others had eyes on it, we didn't lose our control link or video feed, the batteries had plenty of power, and no warning messages were delivered.  The aircraft acted as if it had a mind of its own and simply failed to respond to the left control stick (I was in mode two)--I pushed it straight forward to raise the drone and to avoid yawing.  A witness beside me watched my fingers on the sticks when I said I had no control and corroborated this.    The flight log indicated  that the left stick was pulled back and sideways, and DJI of course put it down to operator error, not a warrantable hardware problem.

I was suspicious that the Cendence controller had played a role and quarantined it---ie didn't use it again.  We had a second Matrice (a 200) and two other Cendance controllers and have used them problem free since then...at this point we have logged 544 flights and 168 hours on these units with no serious issues.  I should say that that we used two Cendences...one as a master and one a slave to control the camera only.  A couple of weeks ago our slave Cendence had a problem (it wouldn't start up---problem with the power switch?) and we took out the quarantined Cendence that we'd used as a master when the 210 crashed in 2018, switched it over to slave function, updated the firmware and began using it to control the camera.  

We noticed right away when we did this that it periodically (every few minutes) lost control of the camera gimbal, which would rotate the camera horizontally and sometimes direct it up.  The problem happened  most often when the camera operator shifted position and moved the Cendence slightly.   The only way to get it control back was to restart the slave controller (or take gimabl control with the master).  For those who haven't used a master and slave arrangment with the Cendence, the slave uses the control sticks to direct the camera up and down and to rotate it horizontally.  
We managed to get hold of a FOURTH Cendence a few days ago, brand new, and in about 20 flights haven't had the sticks lose control of the camera gimble again.  Overall, it seems clear that the defective Cendence issue caused our Matrice crash in 2018.  Moral of the story, if you use a Cendence controller, look out for problems with the control sticks and immediately stop using the unit if anything unexpected happens.  And if you should lose a drone under similar mysterious circumstances to ours, make sure to check whether the controller was at fault--for warranty purposes and also to simply understand what happened.

Here's a cautionary message for those using cendence controllers with Pro Systems.  In 2018 my research team and I lost our new (ish) Matrice 210 when it suddenly spiraled down without warning, landing in the ocean and sinking.  The incident was puzzling at the time because the drone was nearby and I (the operator) and several others had eyes on it, we didn't lose our control link or video feed, the batteries had plenty of power, and no warning messages were delivered.  The aircraft acted as if it had a mind of its own and simply failed to respond to the left control stick (I was in mode two)--I pushed it straight forward to raise the drone and to avoid yawing.  A witness beside me watched my fingers on the sticks when I said I had no control and corroborated this.    The flight log indicated  that the left stick was pulled back and sideways, and DJI of course put it down to operator error, not a warrantable hardware problem.

I was suspicious that the Cendence controller had played a role and quarantined it---ie didn't use it again.  We had a second Matrice (a 200) and two other Cendance controllers and have used them problem free since then...at this point we have logged 544 flights and 168 hours on these units with no serious issues.  I should say that that we used two Cendences...one as a master and one a slave to control the camera only.  A couple of weeks ago our slave Cendence had a problem (it wouldn't start up---problem with the power switch?) and we took out the quarantined Cendence that we'd used as a master when the 210 crashed in 2018, switched it over to slave function, updated the firmware and began using it to control the camera.  

We noticed right away when we did this that it periodically (every few minutes) lost control of the camera gimbal, which would rotate the camera horizontally and sometimes direct it up.  The problem happened  most often when the camera operator shifted position and moved the Cendence slightly.   The only way to get it control back was to restart the slave controller (or take gimabl control with the master).  For those who haven't used a master and slave arrangment with the Cendence, the slave uses the control sticks to direct the camera up and down and to rotate it horizontally.  
We managed to get hold of a FOURTH Cendence a few days ago, brand new, and in about 20 flights haven't had the sticks lose control of the camera gimble again.  Overall, it seems clear that the defective Cendence issue caused our Matrice crash in 2018.  Moral of the story, if you use a Cendence controller, look out for problems with the control sticks and immediately stop using the unit if anything unexpected happens.  And if you should lose a drone under similar mysterious circumstances to ours, make sure to check whether the controller was at fault--for warranty purposes and also to simply understand what happened.