Yes as many as you want. I have 7 on one House/Unit Code Address. All on the same address will follow the On/Off Commands. Few exceptions. Appliance Modules don't follow All Light On Commands on the House Code used; all modules will respond to an All Units Off command on the House Code it is sent to.
You said window modules? Are you talking a Security Console System Door/Window Module? If so they have to register with the console and pick a unique ID when registered.
