What it is and what it does
This Mitsubishi QS0J61BT12 is a CC-Link safety master station in the MELSEC-QS series. It sits on the CC-Link bus as the safety controller, handling remote I/O and registers for up to 64 stations. The module draws 0.46 A from the 5 V backplane supply.
Transmission distance depending on speed
Network cable runs depend on the baud rate selected. At 625 kbps you get 900 m reach; at 2.5 Mbps it drops to 400 m. For faster lines, 5 Mbps covers 160 m and 10 Mbps covers 100 m. Choose the speed that balances throughput against the physical layout of your line.
Safety master specifics
As a safety master station, it manages safe remote stations with CRC32 error checking. Each occupied station provides up to 32 RX/RY points plus 4 RWw/RWr registers when using one station occupancy. Occupying four stations gives 128 remote input and output points each. Total system link points cap at 2048 RX/RY and 256 each of RWr and RWw, which should cover a medium-sized safety cell with multiple remote stations.