Price Sign(Server Version)

This is an APP for manage LED price signs that locate at different place. Price signs are managed in groups. User can query and set the price values showing on the price sign, also brightness. One price sign can show maximum 12 lines of price value, and each line can show cash price and credit price in turn.
There are 4 types of user:
1. Super administrator: the top manager of the system, can add or delete supper operator and general administrator.
2. Super operator: created by super administrator, work as an inspector, can see all information in the system, but no right to change anything.
3. General administrator: created by super operator, can add or delete groups, price signs and general operator, assign rights to general operators.
4. General operator: created by general administrator, detail rights are assigned by the general administrator, has the permission to group as follows: manage group of price sign, configure the price signs, change price value on the price sign, upgrade firmware to the price sign.