SINKING SOURCING I/O
“Sinking” and “Sourcing” terms are very
important in connecting a PLC
correctly with external environment. These terms are applied only for DC
modules.
The most brief definition of these two concepts would be:
SINKING = Common GND line (-)
SOURCING = Common VCC line (+)
correctly with external environment. These terms are applied only for DC
modules.
The most brief definition of these two concepts would be:
SINKING = Common GND line (-)
SOURCING = Common VCC line (+)
Most commonly used DC
module options in PLCs are:
*Sinking input and
*Sourcing output module
*Sinking input and
*Sourcing output module
- Sinking I/O circuits on the I/O modules receive (sink)
current from sourcing field devices. Sinking output modules used for
interfacing with electronic equipment.
- Sourcing I/O: Sourcing output modules used for
interfacing with solenoids.
PLC AC I/O circuits
accommodate either sinking or sourcing field devices. Solid-state DC I/O
circuits require that they used in a specific sinking or sourcing circuit
depending on the internal circuitry.
PLC contact (relay)
output circuits AC or DC accommodate either sinking or sourcing field devices.