Elation DiGidot TX Sending Card
With the DiGidot TX-RX24 kit you can extend the four C4 SPI data outputs up to 250 meters.
If you use DiGidot TX with TTL DMX configured outputs on the DiGidot C4, you get four balanced DMX outputs that can cover up to 500 meters.
Note: In order to send SPI protocols you also need receiver (Rx) modules. The DiGidot TX operates at 5-24 Volts DC and can only be used for Data SPI protocols (Not for Data+Clock).