Schneider-Electric-Zelio-Extendable-Modular-PLC-Schneider-Electric-SR3B101B-This-Zelio-smart-relay-unit-has-a-modular-design-that-makes-it-possible-to-extend-the-operational-capability-The-Zelio-system-is-designed-as-a-PLC-for-small-control-systems-in-industrial-&-building-applications-such-as-finishing-fabrication-assembly-&-packing-machinery-automation-agricultural-machinery-barrier-roller-shutter-access-control-lighting-etc-br-br-The-unit-has-a-built-in-display-that-m