This project seems dead, not only because it hasn't been updated for years but also its nonfunctioning dependency Node-DCOM. Node-DCOM doesn't handle MS DCOM hardening issue as described here, so RPC can't go through at all.
If you really want to use JavaScript to retrieve OPC DA data, take a look at this well-maintained project. Hope it helps!
This project seems dead, not only because it hasn't been updated for years but also its nonfunctioning dependency Node-DCOM. Node-DCOM doesn't handle MS DCOM hardening issue as described here, so RPC can't go through at all.
If you really want to use JavaScript to retrieve OPC DA data, take a look at this well-maintained project. Hope it helps!