DAQ Channels adding. How to add channels in arbitrary order?

I have an NI-cDAQ-chassis 9178 with several modules in it. Particularly an NI 9215 at position 2 and NI 9234 position 4.

If I try to add channels at least one 9234 channel has to be added before the rest and a warning is desplayed. Adding a channel from 9215 first produces and error when adding any channels from 9234. Thanks for your help.

Alex

Compare these codes: 1. This one works:

DAQsession = daq.createSession('ni');
DAQsession.addAnalogInputChannel('cDAQ1Mod4','ai0','Voltage');
% warning appears here
DAQsession.addAnalogInputChannel('cDAQ1Mod2','ai0','Voltage');

2. This one does not:

DAQsession = daq.createSession('ni');
DAQsession.addAnalogInputChannel('cDAQ1Mod2','ai0','Voltage');
DAQsession.addAnalogInputChannel('cDAQ1Mod4','ai0','Voltage');
%{ Error:
NI Error -200077:
Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.
Property: DAQmx_SampTimingType
Requested Value: DAQmx_Val_OnDemand
You Can Select: DAQmx_Val_SampClk
%}