upgrade of Automatically print out a new invoice with bar code

Automatic print out together with barcode when a new order is confirmed after payment page. Background: The past project of automatic print out has been completed by the other developer. It is now functioning properly. At the moment, after a new invoice is created, the printer will automatically print out the receipt. The schedule for “massed invoices processed” is ready, but may need modification for this project. Project nature: Now, I want to upgrade the system further with similar features. 1.) When there is only one computer, I want the printer A to automatically print out for section A for the new invoice. Printer B automatically print out for Section B of restaurant for the new invoice. Printer C automatically print out for Section C of the restaurant. Based on the new invoice created, you will know which section of the restaurant. 2.) You shall also work with another developer to do establish network system for your automatic print out invoice. You will need to guide us or even write additional programs to help us to complete the automatically print out. The purpose of this is to avoid even there is a breakdown of Internet service, the merchant will still able to use our system offline for emergency purpose. 3.) You are required to do this project that is consistent with the already setup automatically print out system. You must understand his current codes, in case of any errors made by past developer in relation to automatic print out. You are required to fix it at free of charge. 4.) Upon completion of project, 5% of total project sum will be withhold as guarantee bond for 3 months. After 3 months, the 5% will be released to you. Notwithstanding with this clause, if we discover any apparent mistake done by you, you are required to fix it within 1 year. For this purpose, you should send your complete work done in freelancer chatroom, so that we will not have arguments on whether your codes may be overwritten by other developers. 5.) You shall work with my project manager, and work accordingly to his specification, such as remarks on codes. 6.) 70% percentage of payments will be released upon test run system. 7.) 25% percentage of payments will be released after real life system is carried out for 2 week. 8.) 5% percentage of payments will be released after 3 months of warranty period. 9.) Current errors that have been detected with current automatic print out invoice system : a. Addition and minus for schedule as per image attached. b. Hide telephone number of member in the invoice, according to the setting of member. 10.) You shall provide guidance as to how to set up printer for automatically. Thank you