How many reading pipes can be open?

Projects Programming
1

I have six unique addresses declared in both my Master Unit Code and my Slave Unit Code

   const uint64_t unitAddresses[6] = { 0xF0F0F0F0AA, 
                                       0xF0F0F0F0BB,
                                       0xF0F0F0F0CC,
                                       0xF0F0F0F0DD,
                                       0xF0F0F0F0EE,
                                       0xF0F0F0F0FF };

In the Master Unit Code setup() I use a loop to initialize each pipe with an individual address

    // open all the reading pipes with their 
    //  individual addresses
    for ( int i=0; i<5; i++ )
    {
      radio.openReadingPipe( i, unitAddresses[ i ] );
    }  //  end for( int i=0;

In the Slave Unit Code setup() I open the reading pipe

    radio.openReadingPipe( slaveNumber, unitAddresses[ slaveNumber ] );

This works fine for Pipe0 but not for the other five. If I set up to communicate with Slave3 (for example) my serial debug printout shows the transmission failing in the Master Unit. It seems to be unable to find Slave3. If I reset for Slave0, all is well again.

2

Sorry, I should have said:

I am using UNOs, TMRh20 RF24.h, and nRF24l01+.