RLY relay modules are frequently added to the AHU controller's binary outputs. You can reuse RLY relay modules when replacing the AHU with an FX-PCA3611. You must wire each RLY relay module to one FX-PCA3611 binary or to one configurable output (configured for binary output mode). If both relays on one RLY relay module are used, you must configure the FX-PCA3611 controller outputs identically. Alternatively, you can replace RLY relay modules with FX-PCX models with onboard relay outputs.
Figure 1. Connecting RLY Relay Modules to FX-PCA3611 Controller