This permanent visa lets a parent of a settled Australian citizen, Australian permanent resident of Australia or eligible New Zealand citizen move to Australia.
You can travel to and from Australia as many times as you want for 5 years from the date, you got this visa. This is as long as the travel facility on this visa remains valid.

⦁ have an eligible child who is a settled Australian citizen, Permanent resident or Eligible New Zealand citizen, unless you are applying for the Retirement Pathway
⦁ meet the balance-of-family test, unless you are applying for the Retirement Pathway or hold a Subclass 173 visa
⦁ have an Assurance of Support, unless you are applying for the Retirement Pathway
⦁ not have already applied for or hold a Sponsored Parent (Temporary) (Subclass 870) visa when applying for this visa

You can apply for the subclass 143 visa as a two-step process by first applying for a Contributory Parent (Temporary) (subclass 173) visa. Applying for the subclass 173 visa and then the subclass 143 visa allows you to spread the cost of the visas over several years.
You have already met the balance of family test.