0
\$\begingroup\$

I want to design a control logic circuit using relay logic. I want to have a bit as a marker as in PLC. Can I use a contactor for this function and then use auxiliary coils as a latch as in PLCs.

\$\endgroup\$
  • \$\begingroup\$ Do you want a temporal or present-state sensing or memory latch? \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Dec 27 '18 at 17:49
0
\$\begingroup\$

Yes.

schematic

simulate this circuit – Schematic created using CircuitLab

Figure 1. A latching relay circuit.

The familiar PLC latching circuit is based on traditional relay logic which came before the PLC.

Just remember that in a PLC the program is executed sequentially whereas in relay logic everything is happening in parallel. This can catch out the unwary when converting from one to the other. Note also that the relay will reset (unlatch) when power is cycled.

| improve this answer | |
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.