Enlisted persons, while on active duty in the service of the state, shall receive the same pay and allowances as enlisted persons of similar grade in the United States Army, United States Air Force, and United States Navy, except that enlisted persons in the pay grade of E1 through E4 ordered to active duty pursuant to Section 143 or 146, while on active duty, shall receive not less than the minimum daily rate of pay applicable to a pay grade of E5 in the active military service of the United States. It is the intent of the Legislature that the foregoing minimum payments to enlisted persons in the pay grade of E1 through E4 may be paid from the State Emergency Fund when, in the judgment of the Director of Finance, there is a case of actual necessity for which no appropriation has been made. All full-time active duty previously or hereafter performed in the service of the state shall be credited for purposes of determining longevity and service within the provisions of this section and Section 340.