Orax SDI automatically updates exchange rates once per day in the early morning. By default some main currencies are available (eg. US Dollar, British Pound, Euro Dollar, etc). You will need to add additional currencies to the currency table if needed. Once a currency is added, Orax SDI will automatically update the exchange rate for that currency on a daily basis.
Currencies need to be configured for your own company and each customer and supplier in the system. The most important currency is the local currency. All financials will be in local currency. If you trade in a foreign currency (configured on customer and supplier accounts) your financials will still record the transaction in local currency. The conversion between foreign and local currency can be setup to dynamically fluctuate on Order or to be fixed. All invoices require fixed exchange rates (they either relate to the exchange rate on the date of the transaction or a manual exchange rate configured for that transaction).
To add or remove foreign currencies go the Company setup, then the Settings. Under financial options is a link to manage foreign currencies.