SPA-ZC21 ABB bus connection module What’s app/Mobile: 86-18020776792 Skpye: miyazheng52 0 Email: miya@mvme.cn (click) Contact our m anager : Miya Product’s description The SPA‑ZC 21 module serves as an interface between a SPACOM device (or other substation‑secondary equipment) and the fibre‑optic SPA bus. It converts incoming optical signals from the SPA bus into electrical signals (RS‑485 or TTL/SPA +5 V) for the host device, and conversely converts the host device’s