The conversion factor from originalAmount.currency -> baseAmount.currency.
Formula: originalAmount.amount / exchangeRate ~= baseAmount.amount
Mandatory when originalAmount.currency != baseAmount.currency
Set to 1.000000000000 when both currencies are the same
Scale: 12 decimal places
Example: Customer pays 108.27 DKK, merchant settles in EUR -> exchangeRate = 7.560750000000 (meaning 1 EUR = 7.560750000000 DKK), baseAmount = 14.32 EUR, originalAmount = 108.27 DKK.
This is the rate from original currency to settlement currency (how many units of original currency equal 1 unit of settlement currency).
Must be greater than or equal to 0.
Must be less than or equal to 100000000000000.
Must be a number with up to 14 integral digits and up to 12 fractional digits.