DAQ session : share trigger connection for analog input and output sessions

Hello,

I have a NI USB-6003 and matlab 2018a, with data acquisition toolbox. I would like to start an analog input session and an analog output session simultaneously, based on an external trigger. On the USB-6003, there are two ports that can be used fort trig-in PFI1 and PFI0. But I want to use only PFI1 for trig-in (because I am using PFI0 as a counter in another session).

So ideally I want to use PFI1 trigger connection to start 2 sessions.

Here is the simpified code I would ideally like to use :

% % % % % -- Analog inputs -- % % % % % 
DAQsessionAI = daq.createSession('ni');
% open a channel
ch0 = DAQsessionAI.addAnalogInputChannel('Dev1','ai0', 'Voltage');

% % % % % -- Analog outputs -- % % % % % 
DAQsessionAO = daq.createSession('ni');
% open a channel
chOut0 = DAQsessionAO.addAnalogOutputChannel('Dev1','ao0', 'Voltage');


% % % % % -- triggering -- % % % % % 
% use PFI1
trigChAI = addTriggerConnection(DAQsessionAI,'external','Dev1/PFI1','StartTrigger');   % trig AI
trigChAO = addTriggerConnection(DAQsessionAO,'external','Dev1/PFI1','StartTrigger');   % trig AO


%% set  analog output (with a dummy output)
DAQsessionAO.Rate = 5000;    % [Hz] sampling rate of signals, max 5000
DAQsessionAO.IsContinuous = true;       % [true/false]. 

% build a dummy output signal
AcqDurationAO = 5;           % [s] total duration of analog output
timeOutput = 0:(1/DAQsessionAO.Rate):AcqDurationAO;        % [s]
f_out = 10;   %[Hz]
outputData = sin(timeOutput.*2.*pi.*f_out)';
queueOutputData(DAQsessionAO,outputData);


%% set analog inputs
DAQsessionAI.Rate = 10000;    % [Hz] sampling rate of signals
DAQsessionAI.IsContinuous = true;         % background acquisition will run until we stop it. 

% listener ( a dummy listener function that simply do : plot(event.TimeStamps, event.Data)  )
lh = addlistener(DAQsessionAI,'DataAvailable', @PlotData); 

%% background acquisition

startBackground(DAQsessionAI);
startBackground(DAQsessionAO);

but when calling startBackground, It get error -89137

NI Error -89137:

Specified route cannot be satisfied, because it requires resources that are currently in use by another route.

Property: DAQmx_DigEdge_StartTrig_Src

Property: DAQmx_DigEdge_StartTrig_Edge

Source Device: Dev1

Source Terminal: PFI1

Required Resources in Use by

Device: Dev1

Reserved Terminal: AO/PFI1

Task Name: _unnamedTask<84>

Status Code: -89137

In a nutshell : Is it possible to share a trigger connection between 2 sessions and how to do it properly ?