Stl sparky

Yes, pelco has built into the protocol commands for aux relays. Several external devices pop up in amazon. Here's one. People use them for dome wipers and flood lighting. https://www.amazon.com/protocol-decoder-control-infrared-wipers/dp/B06Y4DYJ42# Also, i found this guy who makes them https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.sennetech.net/Manuals/SCT_CRX/sct-crx-pelco-relay.pdf&ved=2ahUKEwjkjb_7npXiAhVF-6wKHWxgCy84ChAWMAN6BAgHEAE&usg=AOvVaw2pm_xX6veOxXHL-Im3D17Z