Communications Reference | C |
|
|
Communication Protocols
Communication protocols are important because they determine the transmission standards for communication between the printer and the host. The printer and the host must use the same protocol and parameters to communicate properly. The printer supports the flow control and block transfer protocols described in the next sections. All of these protocols are
Intermec Standard Protocol
Intermec Standard protocol is a proprietary block transfer/status response protocol. For each block sent, the host must wait for the appropriate response before sending the next block (<DC1>). Except for single character status commands (<ENQ> and <VT>), Standard protocol transmits characters in message blocks beginning with the start of text (<STX>) character and ending with the end of text (<ETX>) character. Message blocks can be up to 255 characters, including the start of text and end of text characters. The printer
The printer returns its highest priority status when it receives a valid block (<STX> data <ETX>) or when it receives the status request command <ENQ>. When the printer receives the status dump command (<VT>), the printer returns all active status. The printer status response time ranges from 30ms to 100ms depending on the complexity of the received message block. In the case of a transmission error, the printer responds with a <NAK> and discards the entire message block.
The table below shows printer status conditions in descending order of priority, status response characters, and pin 11/20 states:
Printer Status | Character | Pin 11/20 |
Buffer already full | GS | Busy |
Ribbon fault | US | Busy |
No label stock | EM | Busy |
Buffer now full | DC3 | Busy |
Printhead hot | SI | Busy |
Offline (paused) | DC3 | Busy |
Label at strip pin | FS | Ready |
Skipping | DC1 | Ready |
Printing | DC1 | Ready |
Ready/Online | DC1 | Ready |
Note: Do not confuse the Buffer now full <DC3> status with the XON/XOFF characters <DC1> and <DC3>.
