How to point data table column collection to DataCollection?

Here is my snippet: http://webix.com/snippet/a7de5256

I want the first table to show currency description (‘value’ field) from the second one. Currencies data stored in DataCollection.

Current notation works except the wrong column ID:

{
     id: 'currencyId',
     header: 'Currency',
     fillspace: true,
     collection: currencies
},

http://webix.com/snippet/0ec6b5bc