Siemens SIMATIC S7-1200 Manual page 295

Table A- 16 Wiring diagrams for digital SBs
SB 1221 input module
SB 1221 DI 4 (200 kHz)
①
Supports sourcing inputs only.
Easy Book
Manual, 03/2014, A5E02486774-AF
SB 1222 output module
SB 1222 DQ 4 (200 kHz)
①
For sourcing outputs, connect
"Load" to "-" (shown). For sinking
outputs, connect "Load" to "+".
Because both sinking and sourcing
configurations ae supported by the
same circuitry, the active state of a
sourcing load is opposite that of a
sinking load. A source output exhibits
positive logic (Q bit and LED are ON
when the load has current flow), while a
sink output exhibits negative logic (Q
bit and LED are OFF when the load
has current flow). If the module is
plugged in with no user program, the
default for this module is 0 V, which
means that a sinking load will be turned
ON.
Technical specifications
A.3 Digital I/O modules
SB 1223 input/output module
SB 1223 DI 2 / DQ 2 (200 kHz)
①
Supports sourcing inputs only.
②
For sourcing outputs, connect
"Load" to "-" (shown). For sinking
outputs, connect "Load" to "+".
Because both sinking and sourcing
configurations ae supported by the
same circuitry, the active state of a
sourcing load is opposite that of a
sinking load. A source output exhibits
positive logic (Q bit and LED are ON
when the load has current flow), while a
sink output exhibits negative logic (Q
bit and LED are OFF when the load
has current flow). If the module is
plugged in with no user program, the
default for this module is 0 V, which
means that a sinking load will be turned
ON.
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