Digital channel Stream-Out

I've been testing the T7 Stream-Out to FIO_STATE as a target, via Matlab and a USB connection. The purpose is to trigger a Digitimer DS8R device, which requires a positive edge TTL at 5V (connected to FIO0/GND), at irregular intervals but with precise timing. For testing purposes I'm starting with some low-frequency outputs. It works well for the following example, where I'm outputting alternating 5V and 0V outputs using eWriteNameArray at a scanRate of 1Hz:

[5 0 5 0 5 0 5 0 5 0]

In the above example, the DS8R device correctly triggers 5 times, once every 2s.

However, if I attempt the following output with a scanRate of 2Hz, which should have the same result as example 1 in terms of triggering the DS8R, the end device is only triggered on the first two positive edges:

[5 5 0 0 5 5 0 0 5 5 0 0 5 5 0 0 5 5 0 0]

I get the same problem with this waveform:

[5 0 0 0 5 0 0 0 5 0 0 0 5 0 0 0 5 0 0 0]

I was wondering if I had misunderstood anything about how Stream-Out should work with digital outputs (most of the examples I could find are for analogue outputs)?

Some additional questions I have are:

1. After testing for a while, the Stream-Out stopped working altogether, but then recovered with the following command: eWriteName(handle, 'FIO0', 0). Is there a reason for this, and would it be good practice to set the output channel to 0 before every stream-out?

2. As I read, for Stream-Out without any reading requirements, the scansPerRead parameter is ignored. However, it errors if I set this to zero. I have kept it as scanRate/2 as advised in the documentation - I presume this is ok if it is ignored?

3. Since I've set 'FIO_STATE' as target, will this set all FIO channels to 5V with the above examples? Is it better to specify FIO0 if I am only using this channel, and if so how do I do this?

For reference, a version of my Matlab code is below:

                    % seems to need zeroing
                    name = 'FIO0';
                    value = 0;  
                    LabJack.LJM.eWriteName(h.ljHandle, name, value);
                    
                    % Setup stream-out
                    numAddressesOut = 1;
                    aNamesOut = NET.createArray('System.String', numAddressesOut);
                    aNamesOut(1) = 'FIO_STATE';
                    aAddressesOut = NET.createArray('System.Int32', numAddressesOut);
                    aTypesOut = NET.createArray('System.Int32', numAddressesOut);  
                    LabJack.LJM.NamesToAddresses(numAddressesOut, aNamesOut, ...
                        aAddressesOut, aTypesOut);

                    waveform = [5 0 5 0 5 0 5 0 5 0];

                    scanRate = 1;

                    % Allocate memory for the stream-out buffer
                    buffer_size = max(32,pow2(floor(log2(length(waveform))))*2); 
                    LabJack.LJM.eWriteName(h.ljHandle, 'STREAM_OUT0_ENABLE', 0);
                    LabJack.LJM.eWriteName(h.ljHandle, 'STREAM_OUT0_TARGET', aAddressesOut(1));
                    LabJack.LJM.eWriteName(h.ljHandle, 'STREAM_OUT0_BUFFER_SIZE', buffer_size);
                    LabJack.LJM.eWriteName(h.ljHandle, 'STREAM_OUT0_ENABLE', 1);
                    LabJack.LJM.eWriteName(h.ljHandle, 'STREAM_OUT0_LOOP_NUM_VALUES', 0);
                    LabJack.LJM.eWriteName(h.ljHandle, 'STREAM_OUT0_SET_LOOP', 1);

                    % Load the waveform data points
                    LabJack.LJM.eWriteNameArray(h.ljHandle, 'STREAM_OUT0_BUFFER_U16', length(waveform), waveform, 0);
                    
                    % Setup stream-out
                    numAddressesOut = 1;
                    aNamesOut = NET.createArray('System.String', numAddressesOut);
                    aNamesOut(1) = 'STREAM_OUT0';
                    aAddressesOut = NET.createArray('System.Int32', numAddressesOut);
                    aTypesOut = NET.createArray('System.Int32', numAddressesOut);  
                        LabJack.LJM.NamesToAddresses(numAddressesOut, aNamesOut, ...
                            aAddressesOut, aTypesOut);

                    % Configure and start stream
                    aScanList = aAddressesOut(1); 
                    scansPerRead = scanRate/2; 
                    numAddresses = length(aScanList);

                    [~, scanRate] = LabJack.LJM.eStreamStart(h.ljHandle, scansPerRead, ...
                        numAddresses, aScanList, scanRate);

                    pause(length(h.mwav)/scanRate)

                    % stop stream
                    LabJack.LJM.eStreamStop(h.ljHandle);