Input Characteristic Curve For Digital Inputs - Siemens Simatic M7-400 Reference Manual

Digital Modules

Input Characteristic Curve for Digital Inputs

As long as the current flowing into the module remains v 1.5 mA, the module
recognizes this as a "0" signal.
Typ. switching threshold
I (mA)
E
7
6
BERO
standard
I v 1.5 mA
2
1.5
0.5
– 30 V 0
"0"
2-Wire BERO
Figure 4-1 Input Characteristic Curve for Digital Inputs
IEC 61131, Type 1 in the Case of the Digital Input Module (6ES7421-1BL01-0AA0)
The input current in the case of the digital input module (6ES7421-1BL01-0AA0)
reaches 1.5 mA only above the +5 V switching threshold but under the switching
threshold of the module (typ. 9.5 V). Therefore only type 1 can be specified with the
IEC 61131 standard.
4-16
(9.5 V)
5 11 13 15
"1"
L+
1
I v 1.5 mA
0
M
S7-400, M7-400 Programmable Controllers Module Specifications
Resistance characteristic
curve
I to IEC 61131; type 2
min
I to IEC 61131; type 1
min
24 30 L+ (V)
--> "0" signal
PLC
input resistance
A5E00069467-07