For the 2017 financial year the reasonable amounts for daily travel allowance expenses, according to salary levels, are $97.40 per day for an annual salary of $117,450.00 and below.
For an annual salary of more than $117,451.00 the amount is $106.20 per day.
Please note this will not mean you are able to claim up to these amounts without some form of substantiation or proof of expense claim. This is purely a guide the ATO will use, for example if you were away from home for 200 nights and your salary was $100,000.00, you are not entitled to claim 200 nights @ $97.40 per night = $19,480.00.
The ATO would require some proof to back your claim , ie : receipts paid for meal expenses, travel diaries or menus and price lists from various food outlets.