Description
SIEMENS DIGITAL INPUT SM 1221 6ES7221-1BH32-0XB0
Digital input unit SM 1221, 16DI, DC 24V, Sink/Source.
General information
Product type designation SM 1221, DI 16x24 VDC
Supply voltage
Nominal value (DC) 24 V
Permissible range, lower limit (DC) 20.4 V
Permissible range, upper limit (DC) 28.8 V
Input current
from backplane bus 5 V DC, max. 130 mA
Digital inputs
● from load voltage L+ (no load), max. 4 mA; per channel
output voltage / header
transmitter supply voltage / header
● present Yes
Power dissipated
Power dissipation, typ. 2.5 W
Digital inputs
Number of entrances 16
● in groups of 4
Input characteristic according to IEC 61131, Type 1 Yes
Number of inputs that can be managed simultaneously
all installation positions
— up to 40 °C, max. 16
Horizontal mounting position
— up to 40 °C, max. 16
— up to 50 °C, max. 16
Vertical mounting position
— up to 40 °C, max. 16
Input voltage
● Rated value (DC) 24 V
● for signal "0" 5 V DC with 1 mA
● for signal "1" DC 15 V with 2.5 mA
Input current
● for signal "0", max. (permissible quiescent current) 1 mA
● for signal "1", min. 2.5 mA
● for signal "1", typ. 4 mA
Delay in entry (with nominal input voltage value)
for standard inputs
— parameterizable Yes; 0.2 ms, 0.4 ms, 0.8 ms, 1.6 ms, 3.2 ms, 6.4 ms and 12.8 ms, selectable in groups of 4 for alarm inputs.
