There are 4 slots on the main board to integrate 4 different types of analog/digital I/O boards:
Analog Input Board
• 4 differential or 8 single-ended ±10 V voltage inputs
• 4 single-ended 0-20 mA current inputs
Analog Output Board
• 4 or 8 configurable current or voltage analog outputs
Digital Input Board
• Consisting 8 wide-range digital inputs
Digital Output Board
• Consisting 8 dry contact relay outputs