| Interface | 
RS-485, CS31 protocol | 
| Supply of the module’s electronic circuitry | 
From UP and ZP (power supply) | 
| Supply of the electronic circuitry of the I/O expansion     modules attached | 
Through the expansion bus interface (I/O-Bus) | 
| Address switches | 
For setting the CS31 field bus address (0 to 99) | 
| Digital inputs | 
8 (24 V DC) | 
| Digital inputs/outputs | 
16 (24 V DC) | 
| Fast Counter | 
Integrated, many configurable operating modes | 
| LED displays | 
For system displays, signal statuses, errors and power     supply | 
| External supply voltage | 
Via the terminals ZP and UP (process voltage 24 V DC) |