I have the same problem with SPS - BUS on Man Roland 305+L (1999)
Gives errors with the code:
1) 0910004 Error reading control data.
2) 0901000 No data transfer
3) 0910104 Error transferring data.
4) 1211200 UWR (Control Processor) SPS BUS disconnected
5) 1217600 UWR (Control Computer) Station...