You can send instructions to the printer using multiple programming languages: EPL, ZPL, or SGD. EPL and ZPL commands configure the printer, print labels, and get device status information. SGD commands set and get configuration details. These three languages can be used without the need to send the printer instructions to switch from one language to another.
EPL, ZPL, and SGD commands must be sent to the printer as separate files. They cannot be used together in one format, or set of commands. For example, if you send a series of SGD commands to the printer and they are followed by a printable format, this needs to be done using separate files.