Syncronization of 2 USRP in Reception (master and slave)

[USRP]

Hi,

When I run "niUSRP EX Rx Finite Sync.vi " for the USRP slave device connected to the master via the MIMO cable. I set:
Reference Frequency Source -> MIMO
Timebase Clock Source -> MIMO
I have the following error "niUSRP Initiate.vi <err> The PLL reference clock About did not lock Within the alloted time"

Can you help to resolve this problem?
Can you help me to synchronize two USRP in reception: one slave and the other is the master connected with MIMO cable?

Thank you

[ErikL]

This Error can mean several different things.  To troubleshoot could you try swapping which board is master and which one is slave? Also I would dry a different MIMO cable if you have one.

[USRP]

I set this parameters to the master device that is connected directly to my laptop and10 MHz generator and PPS generator::

IPAdressMaster=192.168.10.2

Reference Frequency Source -> RefIn
Timebase Clock Source -> PpsIn

-----> that's work

However, when i tried with the slave device that is connected to the master via the MIMO cable :

IPAdress=192.168.10.3

Reference Frequency Source -> MIMO
Timebase Clock Source -> MIMO

-----> I have the error mentionned in my first message

Where is the problemem?

this exemple ("niUSRP EX Rx Finite Sync.vi " ) allow us to verify the good working of slave device?

thank you

[ErikL]

When I typically do a master, slave, the master is set to "internal" on Time Ref Source and Freq Ref Source while the slave is set to MIMO for both. If you set them to RefIn and PPS they are looking to the front panel connector.

The way the MIMO cable works is that 10MHz is shared as a square wave over the cable while PPS actually sends digital time stamps (not a PPS signal).

Simple Test Matrix:
1. 10.2 -- internal for both
10.3 -- internal for both
2. 10.2 internal
10.3 MIMO
3. 10.2 MIMO
10.3 Internal

Which cases error?

(MIMO cable can be used in all cases to share Ethernet therefore only 1 Ethernet cable should be used.)

[USRP]

Hi ErikL,

I use one cable ethernet (the master is connected to the laptop and the slave is connected to the master via MIMO cable).

THank you for the information about the pps.

Inspite i do the simple test matrix, I still have error when i set:

IPAdress=192.168.10.3

Reference Frequency Source -> MIMO
Timebase Clock Source -> MIMO

if i set timestamp to 'Next Time Base edge', i have error also!     I have to set timesstamp to zero?

i have to run the two devices simultaneously?  

do you have another idea to test the MIMO in 2 USRP in reception?

Thank you

[USRP · Accepted solution]

HI,

When i run the master and the slave simultaneousely --> i have no error

i use this configuration:

IPAdressMaster=192.168.10.2

Reference Frequency Source -> RefIn
Timebase Clock Source -> PpsIn

IPAdress=192.168.10.3

Reference Frequency Source -> MIMO
Timebase Clock Source -> MIMO

thank you for help