User manual

Chapter Two Installation
man_905-105_2.9 Page 17
achieve this, the input power supply must be above 15VAC or 17VDC. Using these figures, it can
be determined whether there is enough supply for more than one module - allow 100mA for
recharging a battery.
For example, assume there is a 905U-1 module and a 105S-1 module at the same location. The total
I/O at the location is 3 analog inputs, 6 digital inputs and 4 digital outputs. The total load will be :-
TYPE OF LOAD LOAD mA
905U-01 quiescent 85
105S-01 quiescent 45
6 DI @ 10 mA 60
3 AI @ 20mA x 2 120
4 DO @ 25mA 100
Battery charging 100
TOTAL 510
So both modules could be powered from one power supply and one battery, provided the external
supply voltage is more than 15VAC or 17VDC.
2.3.5 24V Regulated Supply
Each module provides a 24V DC regulated supply for analog loop power, except for 905U-4/105S-4.
The supply is rated at 150mA, and should only be used for analog loops.
2.4 Input / Output
2.4.1 Digital Inputs (905-1, 905-2 and 905-4)
The ”-1” and ”-2” modules each provide four digital inputs with 5000 volt opto-isolation, and the ”-4”