Receive buffer size = 32K bytes

4K bytes

2K bytes

Receiving data

X-ON code output

X-OFF code output

Note: Even if each code is ready for output, the same code cannot be transmitted twice successively (except when the power is turned on or the printer is reset from the control panel).

Fig. Buffer in use

(2) Ready/Busy system (see figure)

This is a control system in which the DTR is output at Ready (High) or Busy (Low) level. The DTR, however, is always output at Ready (High) level except the following:

Requirements of output of DTR ‘Busy (Low)’:

When the receive buffer has less than 2K bytes available. When this condition is detected, the printer keeps a ‘Low’ level until the receive buffer has at least 4K bytes available.

6-8

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Citizen CLP-2001 user manual