Intermec 3400

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Communications Reference
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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 point-to-
point except Multi-Drop. Application programs and/or ROM BIOS determine
which protocols your computer can support. For more detailed information,
refer to the Intermec
Data Communications Reference Manual
(Part No. 044737).
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
auto-discriminates between Standard, Polling Mode D, and Multi-Drop
protocols.
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