Specifications

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TM-U230
Specification
(STANDARD)
15 16
2.1.2 IEEE 1284 bidirectional parallel interface (parallel Iinterface specifications)
Copyright© 1994 by the Institute of Electrical and Electronic Engineers, Inc.
2.1.2.1 Specifications
Data transmission: 8-bit parallel
Synchronization: Externally supplied nStrobe signals
Handshaking: nAck and Busy signals
Signal levels: TTL compatible
Connector: 57RE-40360-830B (DDK) or equivalent (IEEE 1284 Type B)
Reverse communication (from printer to host): Nibble or Byte Mode
NOTE: The letter “n” in front of a signal name indicates active LOW.
2.1.2.2 Switching between online and offline
The printer is not equipped with any online/offline switch. The printer is placed in offline status in any
of the following conditions:
• When the power is turned on or until the printer becomes ready for data transmission after it is
initialized by the reset signal (nInit) from the interface.
• During the self-test.
• When the cutter cover is opened.
• During paper feeding using the FEED button.
• When the printer stops printing due to a paper-end.
• When an error has occurred.
2.1.2.3 Reverse mode (data transmission from printer to host)
The STATUS data transmission from the printer to the host proceeds in the Nibble or Byte mode.
• Description
This mode allows data transmission from the asynchronous printer under the control of the host.
Data transmissions in the Nibble Mode are made via the existing control lines in units of four bits (a
Nibble). In the Byte Mode, data transmissions proceed by making the eight-bit data lines
bidirectional.
Both modes fail to proceed concurrently in the Compatibility Mode, thereby causing half duplex
transmission.