The Detcon RL-4 relay output module is a stand-alone serial addressable device. 

Each RL-4 has 4 assignable 5A relay contacts. It receives RS485 Modbus RTU commands that control the 4 relay outputs. RL-4 Modules are din-rail mounted and stackable with slide-in connectors that bus the power and communication lines between modules. 

Modules are serially addressed using front panel switches and the LED flashes to demonstrate valid communications status. 

As serial devices, these RL-4 modules can be located virtually anywhere in a control system scheme. 

The RL-4 module is powered by a 11.5-30 Vdc input and its four relay contacts are rated for 5 A at 30 Vdc and 250 Vac. The relay contacts are single pole double-throw. Each module is designed with integral protection from voltage and current spikes found in typical industrial environments. 

The RL-4 relay output module can be combined with Detcon’s DA-4 (4-20 mA input), AO-4 (4-20 mA output) and DI-4 (contact input) line of I/O modules to create a rugged and reliable control system. 

Control System designs using the Detcon line of I/O modules are low-cost and simplified. 

They provide seamless expandability and simplified field wiring for low-cost installations.