The Orion 32+ series can offer up to 64 Channels going In and Out of your DAW at the same time when the interface is connected with Thunderbolt.
With each of them having only 32 Analog Inputs and Outputs you can leverage the interface’s various digital connectivity options such as SPDIF, MADI, and ADAT to expand your setup.
Note: Keep in mind that this setup is possible only with Thunderbolt connection.
The simplest method is to utilize the Multichannel Audio Digital Interface (MADI). With MADI, you can achieve a maximum of 64 channels for input and output signals, supporting sample rates up to 96kHz. To implement this method, begin by connecting the MADI output of the primary Orion (the one that will utilize Thunderbolt inputs and outputs to connect to the computer) to the MADI inputs of the secondary Orion. Subsequently, connect the MADI outputs of the secondary device to the MADI inputs of the primary device.
Primary Orion Routing:
In the control panel of the primary Orion, navigate to the routing tab. Drag TB PLAY 1-32 to LINE OUT 1-32 and TB PLAY 33-64 to MADI OUT 1-32. Similarly, route LINE IN 1-32 to TB REC 1-32 and MADI IN 1-32 to TB REC 33-64. 
Secondary Orion Routing:
In the control panel of the secondary Orion device, access the routing tab. Drag LINE IN 1-32 to MADI OUT 1-32 and MADI IN 1-32 to LINE OUT 1-32.
MADI Channel Count Considerations
Each MADI connector can independently handle 64 channels. However, at higher sample rates, the channel count decreases. Specifically, users can achieve 64 channels at sample rates of 44.100 and 48.000, while at 88.200 and 96.000 sample rates, the channel count is reduced to 32. It is worth mentioning that higher sample rates such as 176 or 192 preclude the possibility of simultaneously transmitting 64 channels due to MADI's limited capacity for handling large amounts of data.
Clocking Considerations:
Multiple clocking options are available. One option is to transmit the clocking signal from the primary device to the secondary device via the MADI connection, eliminating the need for an additional cable connection. In this case, set the clock source of the secondary device to MADI.
Alternatively, for word clock usage, connect WC OUT 1 or 2 of the primary device to the WC IN of the secondary device. Adjust the clock source of the secondary device to WC accordingly. This applies to SPDIF and ADAT clocking as well, where the signal should always travel from the outputs of the primary device to the inputs of the secondary device.
While all of these methods are viable, using word clock (WC) is recommended
Summary and Practical Setup
In summary, expanding the channel capacity of the Orion 32+ series involves obtaining a second Orion unit and connecting it to the primary unit using MADI. By utilizing all the available analog inputs on both units and transmitting the signals from one unit to the other through a single MADI connector, users can increase the number of analog line inputs beyond the initial 32. This approach offers the added benefits of reduced cable clutter and simplified setup compared to traditional analog connectivity methods.