GE IC693CHS391｜CPU Baseplate｜

Core functionality
Host rack physical carrier
Slot0 fixed installation CPU module; Install the main power supply in the left slot (+optional ACC323B auxiliary power supply); The backplane allocates 5VDC backplane power supply, 24V Relay relay drive bus, isolated 24V I/O bus, and parallel I/O communication bus to all modules.
Local I/O expansion bus interface (25 pin)
The 25 pin interface on the right end is connected to the CHS392 expansion board (local expansion rack) through a dedicated cable; Only for local short-range expansion, cannot do remote I/O; No more CPUs can be placed on the local expansion board, only I/O modules can be used.
Differentiation: Local expansion motherboard ≠ Remote I/O motherboard CHS393/399; Remote I/O requires a NIU unit with a maximum cable length of 213m (700ft).
Power load distribution
All modules plugged into this motherboard are powered by the left power module for 5V current; A 5V current budget must be made, as overloading may result in random module errors, loss of I/O, and CPU abnormalities.
No dip switch, no address setting on the base plate; The slot number is physically fixed, and the module address is determined by the actual slot position.
Hard rules for slot allocation
Leftist: Power slot (PWR/ACC323B), not belonging to slot 10
Slot 0: Only CPU can be placed, I/O modules cannot be placed
Slot 1 Slot 9: I/O, analog, high-speed counting, communication module
Right end 25 pin: Local expansion cable output, cannot connect to remote I/O cable