o_t_data with wrong length

[dfvr1994]

When setting up the communication variables like this:

##### OUTPUT ####
### Parameters for communication from Originator -> Target
eeipclient.o_t_instance_id = 100  # Output instance ID
eeipclient.o_t_length = 12  # Length of the Output data (adjust based on your assembly)
eeipclient.o_t_requested_packet_rate = 100000    # Requested Packet Interval (RPI) in microseconds (100ms)
eeipclient.o_t_realtime_format = RealTimeFormat.HEADER32BIT  # Real-time format  HEADER32BIT, HEARTBEAT, ZEROLENGTH, MODELESS
eeipclient.o_t_owner_redundant = False  # Not redundant
eeipclient.o_t_variable_length = True  # Variable length
eeipclient.o_t_connection_type = ConnectionType.POINT_TO_POINT  # Connection type NULL, MULTICAST, POINT_TO_POINT

##### INPUT ####
### Parameters for communication from Target -> Originator
eeipclient.t_o_instance_id = 110  # Input instance ID
eeipclient.t_o_length = 12  # Length of the Input data (adjust based on your assembly)
eeipclient.t_o_requested_packet_rate = 100000    # Requested Packet Interval (RPI) in microseconds (100ms)
eeipclient.t_o_realtime_format = RealTimeFormat.MODELESS  # Real-time format
eeipclient.t_o_owner_redundant = False  # Not redundant
eeipclient.t_o_variable_length = False  # Fixed length
eeipclient.t_o_connection_type = ConnectionType.POINT_TO_POINT  # Connection type

I am able to see by input as follows:

t_o_data = eeipclient.t_o_iodata
print('t_o input', len(t_o_data), type(t_o_data[0]), t_o_data)

giving:

t_o input 12 <class 'int'> [0, 0, 0, 0, 4, 0, 5, 0, 5, 0, 2, 0]

But when doing the same for the output:

o_t_data = eeipclient.o_t_iodata
print('o_t output', len(o_t_data), type(o_t_data[0]), o_t_data)

I obtain:
o_t output 256 <class 'int'> [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

Which is 256 0s.

What am I missing? The assembly file for the module I'm trying to use is:

AXLFBKEIP_V110.zip