Citizen CLP-2001 user manual 3 RS-232C loopback test, 4 RS-232C protocol

6.2.3RS-232C loopback test

After connector wiring as shown in the figure, turn on the test mode. The printer will receive data that has been transmitted by printer itself and the test of receiving and transmitting data will be performed.

Fig. RS-232C loopback test

6.2.4RS-232C protocol

(1)X-ON/X-OFF system (see figure)

This is a control system in which the data transmitting request signal (X-ON (11H) code) and the data transmitting stop signal (X-OFF (13H) code) are output.

Requirements of output of X-ON code:

•When the power is switched to ON.

•When the receive buffer has less than 2K bytes available, the X- OFF code is output, and the receive buffer has at least 4K bytes available.

Requirements of output of X-OFF code:

• When the receive buffer has less than 2K bytes available.

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