Which feature describes how a PLC discrete output module switches its load?

Which feature describes how a PLC discrete output module switches its load?

• A. Type of Current (AC or DC)
• B. Level of Voltage
• C. Number of Outputs
• D. Solid State or Relay Contact Switching

Answer: (D)

The feature being tested is how a PLC discrete output physically switches the load. It describes the switching mechanism, not the electrical values. Discrete outputs either use solid-state switching, which employs semiconductor devices to turn the load on or off, or relay contacts, which are mechanical contacts that physically connect or disconnect the load. Solid-state switching has no moving parts, so it can switch very quickly and be more compact, but it can have leakage current when off and certain voltage/current limits. Relay contact switching provides true galvanic isolation and can handle higher inrush or inductive loads, but it involves moving parts, so switching is slower and the contacts wear over time. The other options refer to electrical specifications or capacity (whether the system uses AC or DC, the voltage level, or how many outputs exist) rather than the method by which the load is switched.

The feature being tested is how a PLC discrete output physically switches the load. It describes the switching mechanism, not the electrical values. Discrete outputs either use solid-state switching, which employs semiconductor devices to turn the load on or off, or relay contacts, which are mechanical contacts that physically connect or disconnect the load.

Solid-state switching has no moving parts, so it can switch very quickly and be more compact, but it can have leakage current when off and certain voltage/current limits. Relay contact switching provides true galvanic isolation and can handle higher inrush or inductive loads, but it involves moving parts, so switching is slower and the contacts wear over time.

The other options refer to electrical specifications or capacity (whether the system uses AC or DC, the voltage level, or how many outputs exist) rather than the method by which the load is switched.